WorldWideScience

Sample records for leeward wave shadow

  1. Shoreline changes and high-energy wave impacts at the leeward coast of Bonaire (Netherlands Antilles)

    Science.gov (United States)

    Engel, Max; Brückner, Helmut; Messenzehl, Karoline; Frenzel, Peter; May, Simon Matthias; Scheffers, Anja; Scheffers, Sander; Wennrich, Volker; Kelletat, Dieter

    2012-10-01

    Supralittoral coarse-clast deposits along the shores of Bonaire (Netherlands Antilles) as well as increased hurricane frequency during the past decade testify to the major hazard of high-energy wave impacts in the southern Caribbean. Since deducing certain events from the subaerial coarse-clast record involves major uncertainties and historical reports are restricted to the past 500 years, we use a new set of vibracore and push core data (i) to contribute to a more reliable Holocene history of regional extreme-wave events and (ii) to evaluate their impact on shoreline evolution. Multi-proxy palaeoenvironmental analyses (XRF, XRD, grain size distribution, carbonate, LOI, microfossils) were carried out using nearshore sedimentary archives from the sheltered western (leeward) side of Bonaire and its small neighbour Klein Bonaire. In combination with 14C-AMS age estimates the stratigraphy reflects a long-term coastal evolution controlled by relative sea level rise, longshore sediment transport, and short-term morphodynamic impulses by extreme wave action, all three of which may have significantly influenced the development of polyhaline lagoons and the demise of mangrove populations. Extreme wave events may be categorized into major episodic incidents (c. 3.6 ka [?] BP; 3.2-3.0 ka BP; 2.0-1.8 ka BP; post-1.3 ka [?] BP), which may correspond to tsunamis and periodic events recurring on the order of decades to centuries, which we interpret as severe tropical cyclones. Extreme wave events seem to control to a certain extent the formation of coastal ridges on Bonaire and, thus, to cause abrupt shifts in the long-term morphodynamic and ecological boundary conditions of the circumlittoral inland bays.

  2. Determination of the significant wave height from shadowing in synthetic radar images

    NARCIS (Netherlands)

    Wijaya, Andreas Parama; van Groesen, Embrecht W.C.

    2016-01-01

    Radar imagery is nowadays used to observe ocean waves despite the fact that radar images contain invisible areas because of the shadowing effect in the radar mechanism. Moreover, the radar images show the radar intensity which is not directly related to the wave height. This paper deals with the

  3. A ‘Violin-Mode’ shadow sensor for interferometric gravitational wave detectors

    Science.gov (United States)

    Lockerbie, N. A.; Tokmakov, K. V.

    2014-12-01

    This paper describes a system of four novel shadow detectors having, collectively, a displacement sensitivity of (69  ±  13) picometres (rms) / √Hz, at 500 Hz, over a measuring span of ±0.1 mm. The detectors were designed to monitor the vibrations of the 600 mm long, 400 μm diameter, silica suspension fibres of the mirrors for the Advanced LIGO (Laser Interferometer Gravitational wave Observatory) gravitational wave detectors, at the resonances of the so-called Violin Modes (VM). The VM detection system described here had a target sensitivity of 100 pm (rms)/ √Hz at 500 Hz, together with, ultimately, a required detection span of ±0.1 mm about the mean position of each fibre—in order to compensate for potential slow drift over time of fibre position, due to mechanical relaxation. The full sensor system, comprising emitters (sources of illumination) and shadow detectors, therefore met these specifications. Using these sensors, VM resonances having amplitudes of 1.2 nm (rms) were detected in the suspension fibres of an Advanced LIGO dummy test-mass. The VM bandwidth of the sensor, determined by its transimpedance amplifier, was 226 Hz-8.93 kHz at the -3 dB points. This paper focuses mainly on the detector side of the shadow sensors. The emitters are described in an accompanying paper.

  4. A ‘Violin-Mode’ shadow sensor for interferometric gravitational wave detectors

    International Nuclear Information System (INIS)

    Lockerbie, N A; Tokmakov, K V

    2014-01-01

    This paper describes a system of four novel shadow detectors having, collectively, a displacement sensitivity of (69  ±  13) picometres (rms) / √Hz, at 500 Hz, over a measuring span of ±0.1 mm. The detectors were designed to monitor the vibrations of the 600 mm long, 400 μm diameter, silica suspension fibres of the mirrors for the Advanced LIGO (Laser Interferometer Gravitational wave Observatory) gravitational wave detectors, at the resonances of the so-called Violin Modes (VM). The VM detection system described here had a target sensitivity of 100 pm (rms)/ √Hz at 500 Hz, together with, ultimately, a required detection span of ±0.1 mm about the mean position of each fibre—in order to compensate for potential slow drift over time of fibre position, due to mechanical relaxation. The full sensor system, comprising emitters (sources of illumination) and shadow detectors, therefore met these specifications. Using these sensors, VM resonances having amplitudes of 1.2 nm (rms) were detected in the suspension fibres of an Advanced LIGO dummy test-mass. The VM bandwidth of the sensor, determined by its transimpedance amplifier, was 226 Hz–8.93 kHz at the −3 dB points. This paper focuses mainly on the detector side of the shadow sensors. The emitters are described in an accompanying paper. (paper)

  5. Enhancing Wave Energy Competitiveness through Co-Located Wind and Wave Energy Farms. A Review on the Shadow Effect

    Directory of Open Access Journals (Sweden)

    Sharay Astariz

    2015-07-01

    Full Text Available Wave energy is one of the most promising alternatives to fossil fuels due to the enormous available resource; however, its development may be slowed as it is often regarded as uneconomical. The largest cost reductions are expected to be obtained through economies of scale and technological progress. In this sense, the incorporation of wave energy systems into offshore wind energy farms is an opportunity to foster the development of wave energy. The synergies between both renewables can be realised through these co-located energy farms and, thus, some challenges of offshore wind energy can be met. Among them, this paper focuses on the longer non-operational periods of offshore wind turbines—relative to their onshore counterparts—typically caused by delays in maintenance due to the harsh marine conditions. Co-located wave energy converters would act as a barrier extracting energy from the waves and resulting in a shielding effect over the wind farm. On this basis, the aim of this paper is to analyse wave energy economics in a holistic way, as well as the synergies between wave and offshore wind energy, focusing on the shadow effect and the associated increase in the accessibility to the wind turbines.

  6. Quasi-static displacement calibration system for a "Violin-Mode" shadow-sensor intended for Gravitational Wave detector suspensions

    Science.gov (United States)

    Lockerbie, N. A.; Tokmakov, K. V.

    2014-10-01

    This paper describes the design of, and results from, a calibration system for optical linear displacement (shadow) sensors. The shadow sensors were designed to detect "Violin-Mode" (VM) resonances in the 0.4 mm diameter silica fibre suspensions of the test masses/mirrors of Advanced Laser Interferometer Gravitational Wave Observatory gravitational wave interferometers. Each sensor illuminated the fibre under test, so as to cast its narrow shadow onto a "synthesized split photodiode" detector, the shadow falling over adjacent edges of the paired photodiodes. The apparatus described here translated a vertically orientated silica test fibre horizontally through a collimated Near InfraRed illuminating beam, whilst simultaneously capturing the separate DC "shadow notch" outputs from each of the paired split photodiode detectors. As the ratio of AC to DC photocurrent sensitivities to displacement was known, a calibration of the DC response to quasi-static shadow displacement allowed the required AC sensitivity to vibrational displacement to be found. Special techniques are described for generating the required constant scan rate for the test fibre using a DC motor-driven stage, for removing "jitter" at such low translation rates from a linear magnetic encoder, and so for capturing the two shadow-notch signals at each micrometre of the test fibre's travel. Calibration, across the four detectors of this work, gave a vibrational responsivity in voltage terms of (9.45 ± 1.20) MV (rms)/m, yielding a VM displacement sensitivity of (69 ± 13) pm (rms)/√Hz, at 500 Hz, over the required measuring span of ±0.1 mm.

  7. Propagation of acoustic shock waves between parallel rigid boundaries and into shadow zones

    Energy Technology Data Exchange (ETDEWEB)

    Desjouy, C., E-mail: cyril.desjouy@gmail.com; Ollivier, S.; Dragna, D.; Blanc-Benon, P. [Laboratoire de Mécanique des Fluides et d’Acoustique, UMR CNRS 5509, École Centrale de Lyon, Université de Lyon, 69134 Ecully Cedex (France); Marsden, O. [European Center For Medium Range Weather Forecasts, United Kingdom Shinfield (United Kingdom)

    2015-10-28

    The study of acoustic shock propagation in complex environments is of great interest for urban acoustics, but also for source localization, an underlying problematic in military applications. To give a better understanding of the phenomenon taking place during the propagation of acoustic shocks, laboratory-scale experiments and numerical simulations were performed to study the propagation of weak shock waves between parallel rigid boundaries, and into shadow zones created by corners. In particular, this work focuses on the study of the local interactions taking place between incident, reflected, and diffracted waves according to the geometry in both regular or irregular – also called Von Neumann – regimes of reflection. In this latter case, an irregular reflection can lead to the formation of a Mach stem that can modify the spatial distribution of the acoustic pressure. Short duration acoustic shock waves were produced by a 20 kilovolts electric spark source and a schlieren optical method was used to visualize the incident shockfront and the reflection/diffraction patterns. Experimental results are compared to numerical simulations based on the high-order finite difference solution of the two dimensional Navier-Stokes equations.

  8. Analysis on Human Blockage Path Loss and Shadow Fading in Millimeter-Wave Band

    Directory of Open Access Journals (Sweden)

    Hongmei Zhao

    2017-01-01

    Full Text Available Millimeter-wave (Mm-w is the trend of communication development in the future; users who carry mobile communication equipment could be blocked by others in a crowded population environment. Based on Shooting and Bouncing Ray (SBR method and setting up different orientation receivers (RX, population density, and people fabric property at 28 GHz and 38 GHz, simulating experimental scene similar to station square by Wireless Insite software, we use least square method to do linear-regression analysis for path loss and build path loss model. The result shows that the path loss index has a certain change in the different frequency, orientation receivers, population density, and people fabric. The path loss index of RouteC1 and RouteA2 has an obvious change in the central transmitter (TX. Each route shadow fading obeys Gaussian distribution whose mean is 0. This paper’s result has a theoretical guiding for designing the communication system in a crowded population environment.

  9. Evidence for a magma reservoir beneath the Taipei metropolis of Taiwan from both S-wave shadows and P-wave delays.

    Science.gov (United States)

    Lin, Cheng-Horng

    2016-12-23

    There are more than 7 million people living near the Tatun volcano group in northern Taiwan. For the safety of the Taipei metropolis, in particular, it has been debated for decades whether or not these volcanoes are active. Here I show evidence of a deep magma reservoir beneath the Taipei metropolis from both S-wave shadows and P-wave delays. The reservoir is probably composed of either a thin magma layer overlay or many molten sills within thick partially molten rocks. Assuming that 40% of the reservoir is partially molten, its total volume could be approximately 350 km 3 . The exact location and geometry of the magma reservoir will be obtained after dense seismic arrays are deployed in 2017-2020.

  10. Evidence for a magma reservoir beneath the Taipei metropolis of Taiwan from both S-wave shadows and P-wave delays

    Science.gov (United States)

    Lin, Cheng-Horng

    2016-12-01

    There are more than 7 million people living near the Tatun volcano group in northern Taiwan. For the safety of the Taipei metropolis, in particular, it has been debated for decades whether or not these volcanoes are active. Here I show evidence of a deep magma reservoir beneath the Taipei metropolis from both S-wave shadows and P-wave delays. The reservoir is probably composed of either a thin magma layer overlay or many molten sills within thick partially molten rocks. Assuming that 40% of the reservoir is partially molten, its total volume could be approximately 350 km3. The exact location and geometry of the magma reservoir will be obtained after dense seismic arrays are deployed in 2017-2020.

  11. Quasi-static displacement calibration system for a “Violin-Mode” shadow-sensor intended for Gravitational Wave detector suspensions

    International Nuclear Information System (INIS)

    Lockerbie, N. A.; Tokmakov, K. V.

    2014-01-01

    This paper describes the design of, and results from, a calibration system for optical linear displacement (shadow) sensors. The shadow sensors were designed to detect “Violin-Mode” (VM) resonances in the 0.4 mm diameter silica fibre suspensions of the test masses/mirrors of Advanced Laser Interferometer Gravitational Wave Observatory gravitational wave interferometers. Each sensor illuminated the fibre under test, so as to cast its narrow shadow onto a “synthesized split photodiode” detector, the shadow falling over adjacent edges of the paired photodiodes. The apparatus described here translated a vertically orientated silica test fibre horizontally through a collimated Near InfraRed illuminating beam, whilst simultaneously capturing the separate DC “shadow notch” outputs from each of the paired split photodiode detectors. As the ratio of AC to DC photocurrent sensitivities to displacement was known, a calibration of the DC response to quasi-static shadow displacement allowed the required AC sensitivity to vibrational displacement to be found. Special techniques are described for generating the required constant scan rate for the test fibre using a DC motor-driven stage, for removing “jitter” at such low translation rates from a linear magnetic encoder, and so for capturing the two shadow-notch signals at each micrometre of the test fibre's travel. Calibration, across the four detectors of this work, gave a vibrational responsivity in voltage terms of (9.45 ± 1.20) MV (rms)/m, yielding a VM displacement sensitivity of (69 ± 13) pm (rms)/√Hz, at 500 Hz, over the required measuring span of ±0.1 mm

  12. Quasi-static displacement calibration system for a “Violin-Mode” shadow-sensor intended for Gravitational Wave detector suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Lockerbie, N. A.; Tokmakov, K. V. [SUPA (Scottish Universities Physics Alliance), Department of Physics, University of Strathclyde, 107 Rottenrow, Glasgow G4 0NG (United Kingdom)

    2014-10-15

    This paper describes the design of, and results from, a calibration system for optical linear displacement (shadow) sensors. The shadow sensors were designed to detect “Violin-Mode” (VM) resonances in the 0.4 mm diameter silica fibre suspensions of the test masses/mirrors of Advanced Laser Interferometer Gravitational Wave Observatory gravitational wave interferometers. Each sensor illuminated the fibre under test, so as to cast its narrow shadow onto a “synthesized split photodiode” detector, the shadow falling over adjacent edges of the paired photodiodes. The apparatus described here translated a vertically orientated silica test fibre horizontally through a collimated Near InfraRed illuminating beam, whilst simultaneously capturing the separate DC “shadow notch” outputs from each of the paired split photodiode detectors. As the ratio of AC to DC photocurrent sensitivities to displacement was known, a calibration of the DC response to quasi-static shadow displacement allowed the required AC sensitivity to vibrational displacement to be found. Special techniques are described for generating the required constant scan rate for the test fibre using a DC motor-driven stage, for removing “jitter” at such low translation rates from a linear magnetic encoder, and so for capturing the two shadow-notch signals at each micrometre of the test fibre's travel. Calibration, across the four detectors of this work, gave a vibrational responsivity in voltage terms of (9.45 ± 1.20) MV (rms)/m, yielding a VM displacement sensitivity of (69 ± 13) pm (rms)/√Hz, at 500 Hz, over the required measuring span of ±0.1 mm.

  13. A source of illumination for low-noise ‘Violin-Mode’ shadow sensors, intended for use in interferometric gravitational wave detectors

    Science.gov (United States)

    Lockerbie, N. A.; Tokmakov, K. V.; Strain, K. A.

    2014-12-01

    A low-noise source of illumination is described for shadow sensors having a displacement sensitivity of (69  ±  13) picometres (rms)/√Hz, at 500 Hz, over a measuring span of ±0.1 mm. These sensors were designed to detect ‘Violin-Mode’ resonances in the suspension fibres of the test-masses/mirrors for the Advanced LIGO (Laser Interferometer Gravitational wave Observatory) gravitational wave detectors. The source of illumination (emitter) described here used a single column of 8 × miniature near infrared LEDs (λ = 890 nm). These emitters cast the shadows of 400 μm diameter fused silica suspension fibres onto their complementary shadow-displacement detectors, located at a distance of 74 fibre diameters (29.6 mm) behind the axes of the fibres themselves. Violin-Mode vibrations of each fibre were sensed as differential ac photocurrents in the corresponding ‘split-photodiode’ detector. This paper describes the design, construction, noise analysis, and measures that were taken in the conception of the emitters, in order to produce high-contrast shadows at such distant detectors. In this way it proved possible to obtain, simultaneously, a very high transfer sensitivity to Violin-Mode vibration of the fibres, and a very low level of detection noise—close to the fundamental shot noise limit—whilst remaining within the constraints of this simple design of emitter. The shadow detector is described in an accompanying paper.

  14. Shadow art

    KAUST Repository

    Mitra, Niloy J.

    2009-01-01

    "To them, I said, the truth would be literally nothing but the shadows of the images." - Plato, The Republic Shadow art is a unique form of sculptural art where the 2D shadows cast by a 3D sculpture are essential for the artistic effect. We introduce computational tools for the creation of shadow art and propose a design process where the user can directly specify the desired shadows by providing a set of binary images and corresponding projection information. Since multiple shadow images often contradict each other, we present a geometric optimization that computes a 3D shadow volume whose shadows best approximate the provided input images. Our analysis shows that this optimization is essential for obtaining physically realizable 3D sculptures. The resulting shadow volume can then be modified with a set of interactive editing tools that automatically respect the often intricate shadow constraints. We demonstrate the potential of our system with a number of complex 3D shadow art sculptures that go beyond what is seen in contemporary art pieces. © 2009 ACM.

  15. Freshwater fishes from the Leeward Group, Venezuela and eastern Colombia

    NARCIS (Netherlands)

    Beaufort, de L.F.

    1940-01-01

    This paper contains the results of the study of the fish-collection, made by P. Wagenaar Hummelinck, on the islands of the Leeward Group and some parts of the adjacent South-American continent, in 1936—’37 and in 1930. The latter have already been studied by Miss M. Sanders (1936) and are only

  16. Frogs from the Leeward group, Venezuela and eastern Colombia

    NARCIS (Netherlands)

    Brongersma, L.D.

    1948-01-01

    The present notes deal with a small collection of frogs that was made by Dr. P. WAGENAAR HUMMELINCK during his visits to the islands of the Leeward Group, Venezuela and Eastern Colombia. I have included in this study the specimens of Pleurodema brachyops (Cope) already present in the Rijksmuseum van

  17. A source of illumination for low-noise ‘Violin-Mode’ shadow sensors, intended for use in interferometric gravitational wave detectors

    International Nuclear Information System (INIS)

    Lockerbie, N A; Tokmakov, K V; Strain, K A

    2014-01-01

    A low-noise source of illumination is described for shadow sensors having a displacement sensitivity of (69  ±  13) picometres (rms)/√Hz, at 500 Hz, over a measuring span of ±0.1 mm. These sensors were designed to detect ‘Violin-Mode’ resonances in the suspension fibres of the test-masses/mirrors for the Advanced LIGO (Laser Interferometer Gravitational wave Observatory) gravitational wave detectors. The source of illumination (emitter) described here used a single column of 8 × miniature near infrared LEDs (λ = 890 nm). These emitters cast the shadows of 400 μm diameter fused silica suspension fibres onto their complementary shadow-displacement detectors, located at a distance of 74 fibre diameters (29.6 mm) behind the axes of the fibres themselves. Violin-Mode vibrations of each fibre were sensed as differential ac photocurrents in the corresponding ‘split-photodiode’ detector. This paper describes the design, construction, noise analysis, and measures that were taken in the conception of the emitters, in order to produce high-contrast shadows at such distant detectors. In this way it proved possible to obtain, simultaneously, a very high transfer sensitivity to Violin-Mode vibration of the fibres, and a very low level of detection noise—close to the fundamental shot noise limit—whilst remaining within the constraints of this simple design of emitter. The shadow detector is described in an accompanying paper. (paper)

  18. A step-wise steerable source of illumination for low-noise "Violin-Mode" shadow sensors, intended for use in interferometric gravitational wave detectors

    Science.gov (United States)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-01-01

    A steerable low-noise source of illumination is described for shadow-sensors having a displacement sensitivity of ˜100 pm (rms)/√Hz, at 500 Hz, over a measuring span of at least ±0.5 mm. These sensors were designed to detect lateral "Violin-Mode" resonances in the highly tensioned fused-silica suspension fibres of the test-masses/mirrors for the Advanced Laser Interferometer Gravitational Wave Observatory gravitational wave detectors. The shadow sensors—one intended for each of the four fibres in a suspension—comprised a source of Near InfraRed (NIR) radiation (emitter) and a differential shadow-displacement sensor (detector), these bracketing the fibre under test. The suspension fibres themselves were approximately 600 mm long by 0.4 mm in diameter, and when illuminated from the side, they cast narrow, vertical, shadows onto their respective detectors—these being located at an effective distance of 50 fibre diameters behind the axes of the fibres themselves. The emitter described here was designed to compensate for a significant degree of mechanical drift or creep over time in the mean position of its suspension fibre. This was achieved by employing five adjacent columns of 8 × miniature NIR LEDs (Light Emitting Diodes, λ = 890 nm), with one column being activated at a time. When used in conjunction with a "reverse Galilean" telescope, the LED sources allowed the collimated beam from the emitter to be steered azimuthally in fine angular increments (0.65°), causing the fibre's shadow to move laterally, in a step-wise manner, across the plane of its facing detector. Each step in shadow position was approximately 0.23 mm in size, and this allowed the fibre's shadow to be re-centred, so as to bridge once again both elements of its photodiode detector—even if the fibre was off-centred by as much as ±0.5 mm. Re-centring allowed Violin-Mode vibrations of the fibre to be sensed once again as differential AC photocurrents, these flowing in anti-phase in the

  19. A step-wise steerable source of illumination for low-noise “Violin-Mode” shadow sensors, intended for use in interferometric gravitational wave detectors

    International Nuclear Information System (INIS)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-01-01

    A steerable low-noise source of illumination is described for shadow-sensors having a displacement sensitivity of ∼100 pm (rms)/√Hz, at 500 Hz, over a measuring span of at least ±0.5 mm. These sensors were designed to detect lateral “Violin-Mode” resonances in the highly tensioned fused-silica suspension fibres of the test-masses/mirrors for the Advanced Laser Interferometer Gravitational Wave Observatory gravitational wave detectors. The shadow sensors—one intended for each of the four fibres in a suspension—comprised a source of Near InfraRed (NIR) radiation (emitter) and a differential shadow-displacement sensor (detector), these bracketing the fibre under test. The suspension fibres themselves were approximately 600 mm long by 0.4 mm in diameter, and when illuminated from the side, they cast narrow, vertical, shadows onto their respective detectors—these being located at an effective distance of 50 fibre diameters behind the axes of the fibres themselves. The emitter described here was designed to compensate for a significant degree of mechanical drift or creep over time in the mean position of its suspension fibre. This was achieved by employing five adjacent columns of 8  × miniature NIR LEDs (Light Emitting Diodes, λ = 890 nm), with one column being activated at a time. When used in conjunction with a “reverse Galilean” telescope, the LED sources allowed the collimated beam from the emitter to be steered azimuthally in fine angular increments (0.65°), causing the fibre’s shadow to move laterally, in a step-wise manner, across the plane of its facing detector. Each step in shadow position was approximately 0.23 mm in size, and this allowed the fibre’s shadow to be re-centred, so as to bridge once again both elements of its photodiode detector—even if the fibre was off-centred by as much as ±0.5 mm. Re-centring allowed Violin-Mode vibrations of the fibre to be sensed once again as differential AC photocurrents, these flowing in

  20. A step-wise steerable source of illumination for low-noise “Violin-Mode” shadow sensors, intended for use in interferometric gravitational wave detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lockerbie, N. A.; Tokmakov, K. V. [SUPA (Scottish Universities Physics Alliance), Department of Physics, University of Strathclyde, 107 Rottenrow, Glasgow G4 0NG (United Kingdom)

    2016-01-15

    A steerable low-noise source of illumination is described for shadow-sensors having a displacement sensitivity of ∼100 pm (rms)/√Hz, at 500 Hz, over a measuring span of at least ±0.5 mm. These sensors were designed to detect lateral “Violin-Mode” resonances in the highly tensioned fused-silica suspension fibres of the test-masses/mirrors for the Advanced Laser Interferometer Gravitational Wave Observatory gravitational wave detectors. The shadow sensors—one intended for each of the four fibres in a suspension—comprised a source of Near InfraRed (NIR) radiation (emitter) and a differential shadow-displacement sensor (detector), these bracketing the fibre under test. The suspension fibres themselves were approximately 600 mm long by 0.4 mm in diameter, and when illuminated from the side, they cast narrow, vertical, shadows onto their respective detectors—these being located at an effective distance of 50 fibre diameters behind the axes of the fibres themselves. The emitter described here was designed to compensate for a significant degree of mechanical drift or creep over time in the mean position of its suspension fibre. This was achieved by employing five adjacent columns of 8  × miniature NIR LEDs (Light Emitting Diodes, λ = 890 nm), with one column being activated at a time. When used in conjunction with a “reverse Galilean” telescope, the LED sources allowed the collimated beam from the emitter to be steered azimuthally in fine angular increments (0.65°), causing the fibre’s shadow to move laterally, in a step-wise manner, across the plane of its facing detector. Each step in shadow position was approximately 0.23 mm in size, and this allowed the fibre’s shadow to be re-centred, so as to bridge once again both elements of its photodiode detector—even if the fibre was off-centred by as much as ±0.5 mm. Re-centring allowed Violin-Mode vibrations of the fibre to be sensed once again as differential AC photocurrents, these flowing in

  1. Dostoevsky's Shadows

    Directory of Open Access Journals (Sweden)

    Ioana Cristina Nicolae

    2016-04-01

    Full Text Available In this paper, I bring to light Jung’s Shadow archetype in Dostoevsky’s works and also analyzes their implications in the structure of his characters. Taking into account that the Russian writer’s creation is vast, I shall select a limited number of his works, namely ‘The Possessed’; ‘Crime and Punishment’; ‘The Brothers Karamazov’; ‘Notes from Underground’ and ‘The Double’. We are all burdened with our Shadow and must strive to overcome it, but what happens if we fail or never even try to master it? Raskolnikov’s attempt to free himself from the chains of his Shadow was too late, he had already committed the murder, but not in vain, he succeeded in redeeming himself, and so his effort must be taken into account. This does not help him to avoid the punishment, but offers him a chance after serving it. On the other hand, Smerdyakov’s case is different: he made no attempt to overcome his Shadow, the only argument that he brought in his favor being that he acted fuelled by the desire of fulfilling his brother’s wish. It is clear that, he has no chance for a better future and the fault lies with him because he did not create that chance. Dostoevsky’s characters always seem to be ruled by a tragic destiny, an unlucky fate from which they cannot escape.

  2. Shadow Soldiering

    DEFF Research Database (Denmark)

    Mynster Christensen, Maya

    question the thesis pursues is how the processes of mobilisation connecting these constellations are facilitated, and how the constellations are constituted in the intersection between local and global formations. Shadow soldiering, it is argued, is not a phenomenon existing in parallel with...

  3. Shadow Soldiering

    DEFF Research Database (Denmark)

    Mynster Christensen, Maya

    The thesis is an inquiry into what is at stake for a surplus population of militia soldiers in the aftermaths of the civil war in Sierra Leone. The analysis takes its point of departure in how militarised networks are transformed and gradualy morph into new constellations of soldiering. The central......, or in the margins of official political economies. Rather, shadow soldiering is a phenomenon that is becoming increasingly central in the context of security outsourcing and militarisation in a global economy....

  4. Syndrome of extended shadow

    International Nuclear Information System (INIS)

    Ginzburg, M.A.

    1987-01-01

    Syndrome of extended shadow is characterized by large (more than one lobe) or total shadow of the lung area. A detailed roentgenological characteristic and intrasyndrome differential diagnosis of extended shadows is given. Ethiology, pathogenesis and pathomorphology as well as clinical picture and methods of investigation of extended shadows are discussed

  5. Real-time shadows

    CERN Document Server

    Eisemann, Elmar; Assarsson, Ulf; Wimmer, Michael

    2011-01-01

    Important elements of games, movies, and other computer-generated content, shadows are crucial for enhancing realism and providing important visual cues. In recent years, there have been notable improvements in visual quality and speed, making high-quality realistic real-time shadows a reachable goal. Real-Time Shadows is a comprehensive guide to the theory and practice of real-time shadow techniques. It covers a large variety of different effects, including hard, soft, volumetric, and semi-transparent shadows.The book explains the basics as well as many advanced aspects related to the domain

  6. PROPOSALS FOR EDUCATIONAL SPECIFICATIONS, LEEWARD OAHU CAMPUS, HAWAII COMMUNITY COLLEGE SYSTEM.

    Science.gov (United States)

    SWENSON, ROBERT E.

    INITIAL ENROLLMENT FOR THE LEEWARD OAHU CAMPUS IS EXPECTED TO BE 2,000 WITH AN ULTIMATE ENROLLMENT OF ABOUT 5,000. THE PROPOSALS SUBMITTED IN THE PLANNING REPORT CONTAIN MOST OF THE NECESSARY INFORMATION ON EDUCATIONAL PROGRAMS AND FACILITY REQUIREMENTS TO ENABLE THE COMMUNITY COLLEGE STAFF AND THE ARCHITECTS TO PROCEED WITH THE CAMPUS MASTER…

  7. KI-Aikido for Handicapped Students at Leeward Community College: Theory and Practice.

    Science.gov (United States)

    MacGugan, Kirk

    In an effort to provide physical education instruction for handicapped students, Leeward Community College implemented, on a pilot basis, a non-credit course in KI-Aikido, an oriental martial art which combines theory and exercise toward the goal of controlling the body through the power of the mind. The course, offered to both handicapped and…

  8. Shadowing and hyperbolicity

    CERN Document Server

    Pilyugin, Sergei Yu

    2017-01-01

    Focusing on the theory of shadowing of approximate trajectories (pseudotrajectories) of dynamical systems, this book surveys recent progress in establishing relations between shadowing and such basic notions from the classical theory of structural stability as hyperbolicity and transversality. Special attention is given to the study of "quantitative" shadowing properties, such as Lipschitz shadowing (it is shown that this property is equivalent to structural stability both for diffeomorphisms and smooth flows), and to the passage to robust shadowing (which is also equivalent to structural stability in the case of diffeomorphisms, while the situation becomes more complicated in the case of flows). Relations between the shadowing property of diffeomorphisms on their chain transitive sets and the hyperbolicity of such sets are also described. The book will allow young researchers in the field of dynamical systems to gain a better understanding of new ideas in the global qualitative theory. It will also be of int...

  9. Shadowing in dynamical systems

    CERN Document Server

    Pilyugin, Sergei Yu

    1999-01-01

    This book is an introduction to the theory of shadowing of approximate trajectories in dynamical systems by exact ones. This is the first book completely devoted to the theory of shadowing. It shows the importance of shadowing theory for both the qualitative theory of dynamical systems and the theory of numerical methods. Shadowing Methods allow us to estimate differences between exact and approximate solutions on infinite time intervals and to understand the influence of error terms. The book is intended for specialists in dynamical systems, for researchers and graduate students in the theory of numerical methods.

  10. Shadow Toll in Colombia

    OpenAIRE

    González Ruiz, Juan David; Botero Botero, Sergio; Arboleda, Carlos Alejandro; Duque Grisales, Eduardo Alexander

    2015-01-01

    The growing development in infrastructure projects in Colombia has been linked to legal adjustments and capital markets. These two last factors have provided important elements for project developers to design funding strategies. Based on the shadow toll scheme, this paper proposes a new financing strategy for funding highway projects. This strategy may be implemented in Colombia. Finally, the paper proposes future research on shadow toll schemes as a financial mechanism.

  11. Cloud water in windward and leeward mountain forests: The stable isotope signature of orographic cloud water

    Science.gov (United States)

    Scholl, M.A.; Giambelluca, T.W.; Gingerich, S.B.; Nullet, M.A.; Loope, L.L.

    2007-01-01

    Cloud water can be a significant hydrologic input to mountain forests. Because it is a precipitation source that is vulnerable to climate change, it is important to quantify amounts of cloud water input at watershed and regional scales. During this study, cloud water and rain samples were collected monthly for 2 years at sites on windward and leeward East Maui. The difference in isotopic composition between volume‐weighted average cloud water and rain samples was 1.4‰ δ18O and 12‰ δ2H for the windward site and 2.8‰ δ18O and 25‰ δ2H for the leeward site, with the cloud water samples enriched in 18O and 2H relative to the rain samples. A summary of previous literature shows that fog and/or cloud water is enriched in 18O and 2H compared to rain at many locations around the world; this study documents cloud water and rain isotopic composition resulting from weather patterns common to montane environments in the trade wind latitudes. An end‐member isotopic composition for cloud water was identified for each site and was used in an isotopic mixing model to estimate the proportion of precipitation input from orographic clouds. Orographic cloud water input was 37% of the total precipitation at the windward site and 46% at the leeward site. This represents an estimate of water input to the forest that could be altered by changes in cloud base altitude resulting from global climate change or deforestation.

  12. Shadows behind the computers

    CERN Multimedia

    2007-01-01

    EGEE organized a shadowing day to spur female students to take up careers in the IT field. Eleven female staff from CERN’s IT Department were kept under close surveillance last week, shadowed by female students from the Collège du Léman International School as part of the Enabling Grids for E-sciencE project Gender Action Plan. The shadowing day was aimed at inspiring young women to think of careers in information technology, by passing on the message that careers in science are open to both men and women and can be rewarding and fun. The students were given a tour of the ATLAS physics experiment and the CERN Computer Centre, as well as the opportunity for one-to-one interaction with CERN IT staff. Traditionally, fewer women work in the IT sector; women currently represent 21% of EGEE staff. The shadowing day was held as part of the EGEE Gender Action Plan, reflecting a commitment to reducing this gender gap. Other initiatives in...

  13. Impact of large storms on runoff from leeward and windward watersheds, eastern Puerto Rico

    Science.gov (United States)

    Murphy, S. F.; Stallard, R. F.

    2012-12-01

    Water supplies of eastern Puerto Rico are vulnerable to extreme weather events, from severe droughts to powerful tropical storms that cause floods and landslides and damage vegetation and infrastructure. The severity of these events may increase in the future: climate models forecast that the trend of increasing dryness in Puerto Rico will continue, while storm strength may increase due to warmer ocean temperatures. In order to effectively manage water supplies of eastern Puerto Rico, the impact of various weather events needs to be assessed accurately. Precipitation and runoff data over a fifteen-year period were evaluated for four watersheds in eastern Puerto Rico. These watersheds vary in geology, land cover, and location relative to the Luquillo Mountains. Two watersheds windward of the Luquillo Mountains are much wetter, receiving about 4,000 mm precipitation annually, and precipitation is closely related to elevation. Two leeward watersheds receive about half as much precipitation, and precipitation is not well correlated with elevation. Interannual variation in precipitation and runoff is substantial in all four watersheds and is related to regional-scale weather patterns, which are partly explained by large-scale climate oscillations. Greatest precipitation and runoff (both totals and rates) are associated with major storms, such as hurricanes, tropical storms, and upper level troughs. Discharge caused by such storms can be several hundred times greater than average discharge and is a substantial fraction of annual discharge. Rainfall and runoff during the largest storms were similar among all four watersheds, suggesting that higher annual precipitation and runoff in the windward watersheds is probably controlled by the frequent, smaller rain events related to orographic precipitation. The windward/leeward effects dominate hydrologic regimes in these watersheds and overwhelm differences related to bedrock geology or land cover. The impact of reforestation

  14. Rhetorical shadows : The conceptual representation of incongruent shadows

    NARCIS (Netherlands)

    Schilperoord, J; van Weelden, L.|info:eu-repo/dai/nl/362752877

    2018-01-01

    This article addresses the topic of conceptual representation of shadows. We analyze several examples of contemporary imagery, taken from advertising and cartooning, to shed light on the way shadow depictions are used as rhetorical devices. Instead of being inserted as a natural phenomenon,

  15. Canopy water balance of windward and leeward Hawaiian cloud forests on Haleakalā, Maui, Hawai'i

    Science.gov (United States)

    Giambelluca, Thomas W.; DeLay, John K.; Nullet, Michael A.; Scholl, Martha A.; Gingerich, Stephen B.

    2011-01-01

    The contribution of intercepted cloud water to precipitation at windward and leeward cloud forest sites on the slopes of Haleakalā, Maui was assessed using two approaches. Canopy water balance estimates based on meteorological monitoring were compared with interpretations of fog screen measurements collected over a 2-year period at each location. The annual incident rainfall was 973 mm at the leeward site (Auwahi) and 2550 mm at the windward site (Waikamoi). At the leeward, dry forest site, throughfall was less than rainfall (87%), and, at the windward, wet forest site, throughfall exceeded rainfall (122%). Cloud water interception estimated from canopy water balance was 166 mm year−1 at Auwahi and 1212 mm year−1 at Waikamoi. Annual fog screen measurements of cloud water flux, corrected for wind-blown rainfall, were 132 and 3017 mm for the dry and wet sites respectively. Event totals of cloud water flux based on fog screen measurements were poorly correlated with event cloud water interception totals derived from the canopy water balance. Hence, the use of fixed planar fog screens to estimate cloud water interception is not recommended. At the wet windward site, cloud water interception made up 32% of the total precipitation, adding to the already substantial amount of rainfall. At the leeward dry site, cloud water interception was 15% of the total precipitation. Vegetation at the dry site, where trees are more exposed and isolated, was more efficient at intercepting the available cloud water than at the rainy site, but events were less frequent, shorter in duration and lower in intensity. A large proportion of intercepted cloud water, 74% and 83%, respectively for the two sites, was estimated to become throughfall, thus adding significantly to soil water at both sites

  16. Is shadow banking really banking?

    OpenAIRE

    Bryan J. Noeth; Rajdeep Sengupta

    2011-01-01

    To those who don't know, the term "shadow banking" probably has a negative connotation. This primer draws parallels between what has been termed the shadow banking sector and the traditional banking sector—showing that they are similar in many ways.

  17. Water quality in Pearl Harbor and feeder streams during 1971 - 2001 collected primarily by oceanography students from Leeward Community College (NODC Accession 0000590)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water quality data were collected in Pearl Harbor and surrounding feeder streams from 30 December 1971 to 24 August 2001. Data were collected by Leeward Community...

  18. Water quality in Snug Harbor, Oahu, Hawaii, during 1980 - 1998 collected by oceanography students from Leeward Community College (NODC Accession 0000594)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water quality data were collected from FIXED PLATFORMS in Snug Harbor, Hawaii from 01 March 1980 to 30 November 1998. Data were collected by Leeward Community...

  19. Primary productivity in middle loch of Pearl Harbor, Oahu, Hawaii, collected by oceanography students from the Leeward Community College from 1975 to 1996 (NODC Accession 0000655)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Primary productivity data were collected in middle loch of Pearl Harbor, Hawaii, from 20 November 1975 to 27 November 1996. Data were collected by Leeward Community...

  20. The Moon's Phases and the Self Shadow

    Science.gov (United States)

    Young, Timothy; Guy, Mark

    2008-01-01

    In this article, the authors present a new way of teaching the phases of the Moon. Through the introduction of a "self shadow" (an idea of a shadow that is not well-known), they illuminate students' understanding of the phases of the Moon and help them understand the distinction between the shadows that cause eclipses and the shadows that relate…

  1. Out of shadow / Peeter Linnap

    Index Scriptorium Estoniae

    Linnap, Peeter, 1960-

    2007-01-01

    "Out of shadow" oli näitus Baltimaade 1990. aastate kunstist Ameerika publikule - sõnumiks iseseisvumisjärgsete aastate materiaalse, sotsiaalse ning vaimuelu peegeldused/tõlgendused visuaalses kunstis

  2. A prehistoric tsunami induced long-lasting ecosystem changes on a semi-arid tropical island--the case of Boka Bartol (Bonaire, Leeward Antilles).

    Science.gov (United States)

    Engel, Max; Brückner, Helmut; Fürstenberg, Sascha; Frenzel, Peter; Konopczak, Anna Maria; Scheffers, Anja; Kelletat, Dieter; May, Simon Matthias; Schäbitz, Frank; Daut, Gerhard

    2013-01-01

    The Caribbean is highly vulnerable to coastal hazards. Based on their short recurrence intervals over the intra-American seas, high-category tropical cyclones and their associated effects of elevated storm surge, heavy wave impacts, mudslides and floods represent the most serious threat. Given the abundance of historical accounts and trigger mechanisms (strike-slip motion and oblique collision at the northern and southern Caribbean plate boundaries, submarine and coastal landslides, volcanism), tsunamis must be considered as well. This paper presents interdisciplinary multi-proxy investigations of sediment cores (grain size distribution, carbonate content, loss-on-ignition, magnetic susceptibility, microfauna, macrofauna) from Washington-Slagbaai National Park, NW Bonaire (Leeward Antilles). No historical tsunami is recorded for this island. However, an allochthonous marine layer found in all cores at Boka Bartol reveals several sedimentary criteria typically linked with tsunami deposits. Calibrated (14)C data from these cores point to a palaeotsunami with a maximum age of 3,300 years. Alternative explanations for the creation of this layer, such as inland flooding during tropical cyclones, cannot entirely be ruled out, though in recent times even the strongest of these events on Bonaire did not deposit significant amounts of sediment onshore. The setting of Boka Bartol changed from an open mangrove-fringed embayment into a poly- to hyperhaline lagoon due to the establishment or closure of a barrier of coral rubble during or subsequent to the inferred event. The timing of the event is supported by further sedimentary evidence from other lagoonal and alluvial archives on Bonaire.

  3. Unitarity bound for gluon shadowing

    International Nuclear Information System (INIS)

    Kopeliovich, B. Z.; Levin, E.; Potashnikova, I. K.; Schmidt, Ivan

    2009-01-01

    Although at small Bjorken x gluons originated from different nucleons in a nucleus overlap in the longitudinal direction, most of them are still well separated in the transverse plane and therefore cannot fuse. For this reason the gluon density in nuclei cannot drop at small x below a certain bottom bound, which we evaluated in a model independent manner assuming the maximal strength of gluon fusion. We also calculated gluon shadowing in the saturated regime using the Balitsky-Kovchegov equation and found the nuclear ratio to be well above the unitarity bound. The recently updated analysis of parton distributions in nuclei, including BNL Relativistic Heavy Ion Collider (RHIC) data on high-p T hadron production at forward rapidities, led to strong gluon shadowing. Such strong shadowing and therefore the interpretation of the nuclear modification of the p T spectra in dA collisions at RHIC seem to be inconsistent with this unitarity bound.

  4. Innocent Body-Shadow Mimics Physical Body

    Directory of Open Access Journals (Sweden)

    Kenri Kodaka

    2017-04-01

    Full Text Available The paradigm of the rubber hand illusion was applied to a shadow to determine whether the body-shadow is a good candidate for the alternative belonging to our body. Three kinds of shadows, a physical hand, a hand-shaped cloth, and a rectangle cloth, were tested for this purpose. The questionnaire results showed that both anatomical similarity and visuo-proprioception correlation were effective in enhancing illusory ownership of the shadow. According to the proprioceptive drift measurement, whether the shadow purely originated from the physical body was a critical factor in yielding the significantly positive drift. Thus, results demonstrated that the shadow can distort illusory ownership with the rubber hand illusion paradigm, but the proprioception was clearly distorted only when the body-shadow was purely applied. This implies the presence of special cognitive processing to discriminate the self-body shadow from the others.

  5. Study on Processing Method of Image Shadow

    Directory of Open Access Journals (Sweden)

    Wang Bo

    2014-07-01

    Full Text Available In order to effectively remove disturbance of shadow and enhance robustness of information processing of computer visual image, this paper makes study on inspection and removal of image shadow. It makes study the continual removal algorithm of shadow based on integration, the illumination surface and texture, it respectively introduces their work principles and realization method, it can effectively carrying processing for shadow by test.

  6. Shadow imaging of geosynchronous satellites

    Science.gov (United States)

    Douglas, Dennis Michael

    Geosynchronous (GEO) satellites are essential for modern communication networks. If communication to a GEO satellite is lost and a malfunction occurs upon orbit insertion such as a solar panel not deploying there is no direct way to observe it from Earth. Due to the GEO orbit distance of ~36,000 km from Earth's surface, the Rayleigh criteria dictates that a 14 m telescope is required to conventionally image a satellite with spatial resolution down to 1 m using visible light. Furthermore, a telescope larger than 30 m is required under ideal conditions to obtain spatial resolution down to 0.4 m. This dissertation evaluates a method for obtaining high spatial resolution images of GEO satellites from an Earth based system by measuring the irradiance distribution on the ground resulting from the occultation of the satellite passing in front of a star. The representative size of a GEO satellite combined with the orbital distance results in the ground shadow being consistent with a Fresnel diffraction pattern when observed at visible wavelengths. A measurement of the ground shadow irradiance is used as an amplitude constraint in a Gerchberg-Saxton phase retrieval algorithm that produces a reconstruction of the satellite's 2D transmission function which is analogous to a reverse contrast image of the satellite. The advantage of shadow imaging is that a terrestrial based redundant set of linearly distributed inexpensive small telescopes, each coupled to high speed detectors, is a more effective resolved imaging system for GEO satellites than a very large telescope under ideal conditions. Modeling and simulation efforts indicate sub-meter spatial resolution can be readily achieved using collection apertures of less than 1 meter in diameter. A mathematical basis is established for the treatment of the physical phenomena involved in the shadow imaging process. This includes the source star brightness and angular extent, and the diffraction of starlight from the satellite

  7. Differential denudation across the Judea Range, Israel, suggests the persistence of a rain-shadow since mid Miocene

    Science.gov (United States)

    Ryb, U.; Matmon, A.; Erel, Y.; Haviv, I.; Benedetti, L. C.

    2013-12-01

    The Judea Range which is composed of a thick sequence of Cretaceous marine carbonate rises up to ~1000 m between the Mediterranean Sea and the Dead Sea basins. The western flank of the range faces predominant winds which deliver humidity from the Mediterranean and thus maintains a sub-humid Mediterranean climate (Mean Annual Precipitation (MAP) of 500-700 mm). Over the eastern, leeward side, rain-shadow orographic effect imposes a climatic gradient from Mediterranean near the water divide to hyper-arid near the Dead Sea rift escarpment (MAPMAP values, indicating that chemical weathering is the dominant process of erosion. Long-term denudation rates of interfluves reflect the climatic gradient between the two flanks of the Judea range; over the western, windward, flank of the Judea range, exposed bedrock denude at an average rate of 21×7 mm kyr-1, while over the leeward flank denudation rates drop dramatically, reaching 1-3 mm kyr-1 near the Dead Sea rift escarpment. As a rough measure to the erosion of the Judea Range since it began uplifting in Senonian time, we compare the present envelope-topography (T) of the range with the top-Turonian structural datum (S). We found that over the windward flank topography lay ~300 meters below the datum, while over the leeward flank topography generally follows the datum. Can this difference result from differential denudation, similar to the one observed over 10-1-105 year timescales? S-T values are well correlated with present MAP values, suggesting a positive answer. Assuming that the late Pleistocene denudation pattern calculated from 36Cl data was maintained, ~15 million years are required to form the observed 300 difference between the eastern and western flanks of the range. Indeed, previous studies suggest that by mid Miocene the Judea Range was uplifted to about ~500 m above sea level, while the Mediterranean was the immediate source for humidity in the region as of the early Miocene. The integrated data could

  8. Chromatic Shadow Detection and Tracking for Moving Foreground Segmentation

    DEFF Research Database (Denmark)

    Huerta, Ivan; Holte, Michael Boelstoft; Moeslund, Thomas B.

    2015-01-01

    Advanced segmentation techniques in the surveillance domain deal with shadows to avoid distortions when detecting moving objects. Most approaches for shadow detection are still typically restricted to penumbra shadows and cannot cope well with umbra shadows. Consequently, umbra shadow regions are...

  9. Moving Shadow Detection in Video Using Cepstrum

    Directory of Open Access Journals (Sweden)

    Fuat Cogun

    2013-01-01

    Full Text Available Moving shadows constitute problems in various applications such as image segmentation and object tracking. The main cause of these problems is the misclassification of the shadow pixels as target pixels. Therefore, the use of an accurate and reliable shadow detection method is essential to realize intelligent video processing applications. In this paper, a cepstrum-based method for moving shadow detection is presented. The proposed method is tested on outdoor and indoor video sequences using well-known benchmark test sets. To show the improvements over previous approaches, quantitative metrics are introduced and comparisons based on these metrics are made.

  10. Giant atoms cast long shadow

    International Nuclear Information System (INIS)

    Amato, I.

    1996-01-01

    Atoms swollen with energy can serve as supersensitive detectors. They also probe the shadow realm where the quantum world of the atom gives way to the familiar classical world. Created in the laboratory, where they live for a few milliseconds inside vacuum chambers, Rydberg atoms acquire their girth when one or sometimes two of their electrons are excited to very high energy levels, displacing them far from the nuclear core. This article describes the atoms, the history of their identification, and future possibilities. 2 figs

  11. Shadows Along the Spiritual Pathway.

    Science.gov (United States)

    Humphrey, Caroline

    2015-12-01

    Contemporary spirituality discourses tend to assume that a canopy of light and love overarches all spiritual pathways. Unfortunately, the dark side of humanity cannot be spirited away so easily, and aberrations of personal spiritual development, interpersonal spiritual relationships and new spiritual movements can often be traced to the denial, repression and return of our dark side. Transpersonal psychology offers a way of approaching, reframing and redeeming the unconscious depths of our psyche, with its metaphors of shadows and daimons on the one hand, and its therapeutic practices for symbolically containing and transcending polarities on the other. In its absence, any spirituality which eulogises holistic growth is likely to engender the reverse effect.

  12. Projectors, Shadows, and Conformal Blocks

    OpenAIRE

    Simmons-Duffin, David

    2012-01-01

    We introduce a method for computing conformal blocks of operators in arbitrary Lorentz representations in any spacetime dimension, making it possible to apply bootstrap techniques to operators with spin. The key idea is to implement the “shadow formalism” of Ferrara, Gatto, Grillo, and Parisi in a setting where conformal invariance is manifest. Conformal blocks in d -dimensions can be expressed as integrals over the projective null-cone in the “embedding space” $ \\mathbb{R} $ d +1,1 . Taking ...

  13. Wave

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo

    2008-01-01

    Estimates for the amount of potential wave energy in the world range from 1-10 TW. The World Energy Council estimates that a potential 2TW of energy is available from the world’s oceans, which is the equivalent of twice the world’s electricity production. Whilst the recoverable resource is many...

  14. Prevalence of pox-like lesions and malaria in forest bird communitites on leeward Mauna Loa volcano, Hawaii

    Science.gov (United States)

    Atkinson, C.T.; Lease, J.K.; Dusek, Robert J.; Samuel, M.D.

    2005-01-01

    Introduced avian pox virus and malaria have had devastating impacts on native Hawaiian forest birds, yet little has been published about their prevalence and distribution in forest bird communities outside of windward Hawaii Island. We surveyed native and non-native forest birds for these two diseases at three different elevations on leeward Mauna Loa Volcano at the Kona Forest Unit of Hakalau Forest National Wildlife Refuge. Prevalence of malaria by both serology and microscopy varied by elevation and ranged from 28% at 710 m to 13% at 1830 m. Prevalence of pox-like lesions also varied by altitude, ranging in native species from 10% at 710 m to 2% at 1830 m. Native species at all elevations had the highest prevalence of malarial antibody and pox-like lesions. By contrast, pox-like lesions were not detected in individuals of four non-native species and only 5% of Japanese White-eye (Zosterops japonicus) was positive for malaria. A significantly high proportion of birds with pox-like lesions also had serological evidence of concurrent, chronic malarial infections, suggesting an interaction between these diseases, dual transmission of both diseases by the primary mosquito vector (Culex quinquefasciatus) or complete recovery of some pox-infected birds without loss of toes. Results from this study document high prevalence of malaria and pox at this refuge. Development of effective disease control strategies will be important for restoration of remnant populations of the endangered 'Akiapola'au (Hemignathus munroi), Hawaii Creeper (Oreomystis mana), and Hawaii 'Akepa (Loxops coccineus coccineus) that still occur on the refuge.

  15. Detection of Cast Shadows in Surveillance Applications

    DEFF Research Database (Denmark)

    Erbou, Søren G.; Sørensen, Helge Bjarne Dissing; Stage, Bjarne

    2005-01-01

    Cast shadows from moving objects reduce the general ability of robust classification and tracking of these objects, in outdoor surveillance applications. A method for segmentation of cast shadows is proposed, combining statistical features with a new similarity feature, derived from a physics...

  16. Projectors, shadows, and conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Simmons-Duffin, David [Jefferson Physical Laboratory, Harvard University,Cambridge, MA 02138 (United States)

    2014-04-24

    We introduce a method for computing conformal blocks of operators in arbitrary Lorentz representations in any spacetime dimension, making it possible to apply bootstrap techniques to operators with spin. The key idea is to implement the “shadow formalism' of Ferrara, Gatto, Grillo, and Parisi in a setting where conformal invariance is manifest. Conformal blocks in d-dimensions can be expressed as integrals over the projective null-cone in the “embedding space' ℝ{sup d+1,1}. Taking care with their analytic structure, these integrals can be evaluated in great generality, reducing the computation of conformal blocks to a bookkeeping exercise. To facilitate calculations in four-dimensional CFTs, we introduce techniques for writing down conformally-invariant correlators using auxiliary twistor variables, and demonstrate their use in some simple examples.

  17. Gaining Control of Iraq's Shadow Economy

    National Research Council Canada - National Science Library

    Ramirez, David S

    2007-01-01

    .... These conditions fuel a sprawling, decades-old shadow economy manipulated by elements of organized crime, militias, and insurgents to fund attacks on Coalition forces, infrastructure and innocent Iraqi civilians...

  18. Fading and shadowing in wireless systems

    CERN Document Server

    Shankar, P Mohana

    2017-01-01

    This book offers a comprehensive overview of fading and shadowing in wireless channels. A number of statistical models including simple, hybrid, compound and cascaded ones are presented along with a detailed discussion of diversity techniques employed to mitigate the effects of fading and shadowing. The effects of co-channel interference before and after the implementation of diversity are also analyzed. To facilitate easy understanding of the models and the analysis, the background on probability and random variables is presented with relevant derivations of densities of the sums, products, ratios as well as order statistics of random variables. The book also provides material on digital modems of interest in wireless systems. The updated edition expands the background materials on probability by offering sections on Laplace and Mellin transforms, parameter estimation, statistical testing and receiver operating characteristics. Newer models for fading, shadowing and shadowed fading are included along with th...

  19. Gaining Control of Iraq's Shadow Economy

    National Research Council Canada - National Science Library

    Ramirez, David S

    2007-01-01

    .... The shadow economy is also used extensively by the poor and women for subsistence living. The combined effect for Iraqi citizens is they have to survive in a country without adequate institutions and poor governance...

  20. The little book of light and shadow

    CERN Document Server

    Thornton, Linda

    2013-01-01

    Encourage your Early Learners to becom investigators by exploring the concept of light and shadow. These simple and effective activities can be carried out independently with the focus on natural resources.

  1. Shadow photography method for beam emittance measurement

    International Nuclear Information System (INIS)

    Kashkovskij, V.V.; Lisin, V.A.

    1988-01-01

    Improved technique of shadow photography which allows to measure rather simply and accurately the angular distribution of electrons extracted from betatron is described. Measurement accuracy of particle flight angles is determined by setting of rods relatively to the plane of photographic paper sheet, their diameter and shadow trace length. Incidental angle deviation of rod axes contributes mainly into the error. Mean root-square error constituted 2-3% according to the results of several measurements of angles

  2. Location Verification Systems Under Spatially Correlated Shadowing

    OpenAIRE

    Yan, Shihao; Nevat, Ido; Peters, Gareth W.; Malaney, Robert

    2014-01-01

    The verification of the location information utilized in wireless communication networks is a subject of growing importance. In this work we formally analyze, for the first time, the performance of a wireless Location Verification System (LVS) under the realistic setting of spatially correlated shadowing. Our analysis illustrates that anticipated levels of correlated shadowing can lead to a dramatic performance improvement of a Received Signal Strength (RSS)-based LVS. We also analyze the per...

  3. Investigation of the Stability via Shadowing Property

    Directory of Open Access Journals (Sweden)

    Koh Heejeong

    2009-01-01

    Full Text Available The shadowing property is to find an exact solution to an iterated map that remains close to an approximate solution. In this article, using shadowing property, we show the stability of the following equation in normed group: , where , and is a mapping. And we prove that the even mapping which satisfies the above equation is quadratic and also the Hyers-Ulam stability of the functional equation in Banach spaces.

  4. Evaluation of Digital Shadow Economy Prevention Measures

    Directory of Open Access Journals (Sweden)

    Remeikiene Rita

    2016-06-01

    Full Text Available Although during the past few years the scopes of shadow economy in Lithuania have slightly decreased, different forms of this phenomenon, in particular digital shadow activities, still generate a significant part of the overall value added. As no constant estimations of the scope of digital shadow economy have been made in Lithuania, alleviation of this problem is based on consequence fighting rather than reason elimination. Digital shadow economy poses a significant challenge for law enforcement agencies concerning its investigation and prevention. Hence, it is purposeful to research both theoretical and practical aspects of digital shadow economy prevention in order to identify the measures that could be used for the efficient reduction of the scope of this phenomenon. The aim of this research is to identify the measures of digital shadow economy prevention and compare the attitudes of governmental institutions and consumers towards the efficiency of these measures. The results of the empirical research showed that both consumers and experts agree that the level of tax morale has to be raised not only by using the measures of self-education but also by introducing long-term educational programmes; second, public authorities should ensure business friendly environment, actively implement the principles of justice and officially acknowledge and announce the concept of digital shadow economy; finally, for more efficient detection of the cases of digital shadow activities, it is necessary to reinforce current labour resources that should be specially trained to be able to disclose revenue hiding and tax evasion schemes, employed in e-trade.

  5. Exposing photo manipulation using geometry and shadows

    Science.gov (United States)

    Zheng, Jiangbin; Song, Xuemei; Ren, Jinchang; Zhu, Tingge

    2014-04-01

    It is increasingly easier to manipulate digital images by the sophisticated photo editing software. Often visual inspection cannot definitively distinguish manipulation from authentic images. This paper introduces a forensic technique that focuses on geometric and shadow color inconsistencies which arise when fake objects with shadows are inserted into an image or an object with its shadow in the image are modified. This paper analyzes three underlying geometric relations and shadow color characteristic constrains that occur in image scene. In particular, (i) explore the property of vanishing point in linear perspective project, and evaluate the geometric consistent level of the image based on the uncertain degree of vanishing point;(ii) analyze the relation between illuminated object and its cast shadow which are modeled by the planar homology and use this constrain to estimate the image's geometric consistent level;(iii) locate tempered region by measure the K-L divergence between shadow pairs. Visually plausible forgery images demonstrate the performance of our proposed method.

  6. The shadow response of the cockroach periplaneta americana.

    Science.gov (United States)

    Meyer, D J; Margiotta, J F; Walcott, B

    1981-01-01

    We show that the "escape response" (running) of the cockroach Periplaneta americana is interrupted when the insect runs through a shadow. Shadows were cast by holding an opaque plastic sheet so that the cockroach ran beneath it. In control experiments, a similarly positioned clear plastic sheet was ineffective. Removal of the shadow stimulus allowed running to continue. The likelihood that cockroaches would resume running after removal of the shadow stimulus decreased with the time they were allowed to remain in shadow.

  7. Development of the shadow banking system in Zimbabwe: A blessing from the shadows?

    Directory of Open Access Journals (Sweden)

    Misheck Mutize

    2015-10-01

    Full Text Available The rising of shadow banking institutions in Zimbabwe has been very quick for formal banking institutions and regulators to strategise against the threats that came with their development. This study applied qualitative data analysis and find that, the growth of a shadow banking system was market driven. Lack of confidence and financial innovation on the mainstream banking system to structure financial products that improve intermediation gave space for shadow banking growth. In response to this development, the researcher recommended that regulatory focus should be on the functions of shadow banks rather than institutions; this will be more inclusive and efficient in avoiding innovative creation of new entities that perform the same shadow banking functions. Also, the Zimbabwean formal banking system should be innovative in-line with the development of the international banking models.

  8. Improving Students’ Listening Skill Through Shadowing

    Directory of Open Access Journals (Sweden)

    Mukminatus Zuhriyah

    2016-12-01

    Full Text Available Listening is the first part of language skills that everyone gets when learning a language. It comes before speaking, reading, and writing. Meanwhile, most of the students get difficulty to learn listening of a foreign language, especially English. That is why shadowing was applied in the listening class as one of the solutions to make the learners of English listening easy to understand what the speaker says. This collaborative classroom action research was generally to know whether or not shadowing could improve the students listening skill. It was also specifically to know: (1 the lecturer’s activities, (2 the students’ activities, and (3 the students’ responses during the implementation of shadowing in the listening class. The subjects were 18 students of the third semester of English department of education faculty of Hasyim Asy’ari university (UNHASY Tebuireng Jombang in the academic year of 2016/2017. The data were obtained from the observations got from the notes written by the collaborator and the listening test. The students’ listening skill improved after the implementation of shadowing. It could be seen in the improvement of mean score, from 74.2 in cycle one to 75 in cycle two. Then, the precentage of students passing the minimum mastery criteria also improved, from 61% in cycle one to 77.8% in cycle two. Thus, it can be concluded that shadowing could improve students’ listening skill.

  9. Shadows alter facial expressions of Noh masks.

    Directory of Open Access Journals (Sweden)

    Nobuyuki Kawai

    Full Text Available BACKGROUND: A Noh mask, worn by expert actors during performance on the Japanese traditional Noh drama, conveys various emotional expressions despite its fixed physical properties. How does the mask change its expressions? Shadows change subtly during the actual Noh drama, which plays a key role in creating elusive artistic enchantment. We here describe evidence from two experiments regarding how attached shadows of the Noh masks influence the observers' recognition of the emotional expressions. METHODOLOGY/PRINCIPAL FINDINGS: In Experiment 1, neutral-faced Noh masks having the attached shadows of the happy/sad masks were recognized as bearing happy/sad expressions, respectively. This was true for all four types of masks each of which represented a character differing in sex and age, even though the original characteristics of the masks also greatly influenced the evaluation of emotions. Experiment 2 further revealed that frontal Noh mask images having shadows of upward/downward tilted masks were evaluated as sad/happy, respectively. This was consistent with outcomes from preceding studies using actually tilted Noh mask images. CONCLUSIONS/SIGNIFICANCE: Results from the two experiments concur that purely manipulating attached shadows of the different types of Noh masks significantly alters the emotion recognition. These findings go in line with the mysterious facial expressions observed in Western paintings, such as the elusive qualities of Mona Lisa's smile. They also agree with the aesthetic principle of Japanese traditional art "yugen (profound grace and subtlety", which highly appreciates subtle emotional expressions in the darkness.

  10. Shadowing effects on vector boson production

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, R.

    2000-11-10

    We explore how nuclear modifications to the nucleon structure functions, shadowing, affect massive gauge boson production in heavy ion collisions at different impact parameters. We calculate the dependence of Z{sup 0}, W{sup +} and W{sup -} production on rapidity and impact parameter to next-to-leading order in Pb+Pb collisions at 5.5 TeV/nucleon to study quark shadowing at high Q{sup 2}. We also compare our Pb+Pb results to the pp rapidity distributions at 14 TeV.

  11. Detection and Removal of Chromatic Moving Shadows in Surveillance Scenarios

    DEFF Research Database (Denmark)

    Casado, Ivan Huerta; Holte, Michael Boelstoft; Moeslund, Thomas B.

    2009-01-01

      Segmentation in the surveillance domain has to deal with shadows to avoid distortions when detecting moving objects. Most segmentation approaches dealing with shadow detection are typically restricted to penumbra shadows. Therefore, such techniques cannot cope well with umbra shadows....... Consequently, umbra shadows are usually detected as part of moving objects. In this paper we present a novel technique based on gradient and colour models for separating chromatic moving cast shadows from detected moving objects. Firstly, both a chromatic invariant colour cone model and an invariant gradient...... model are built to perform automatic segmentation while detecting potential shadows. In a second step, regions corresponding to potential shadows are grouped by considering "a bluish effect" and an edge partitioning. Lastly, (i) temporal similarities between textures and (ii) spatial similarities...

  12. Shadow mask evaporation through monolayer modified nanostencils

    NARCIS (Netherlands)

    Kolbel, M.; Tjerkstra, R.W.; Brugger, J.P.; van Rijn, C.J.M.; Nijdam, W.; Huskens, Jurriaan; Reinhoudt, David

    2002-01-01

    Gradual clogging of the apertures of nanostencils used as miniature shadow masks in metal evaporations can be reduced by coating the stencil with self-assembled monolayers (SAM). This is quantified by the dimensions (height and volume) of gold features obtained by nanostencil evaporation as measured

  13. Hunting the Shadow, Catching the Light

    DEFF Research Database (Denmark)

    Toft, Anne Elisabeth; Nielsen, Torben

    2009-01-01

    From 28 October to 6 November 2009 twenty-one 3rd year students in interior design from Central Academy of Fine Arts (CAFA), School of Architecture, Beijing participated in the workshop Hunting the Shadow - Catching the Light. The workshop was conceived and led by the Danish architects Torben...

  14. Shadow Science: Astronomy in the Schoolyard

    Science.gov (United States)

    Denney, Janice

    2005-01-01

    It is natural to study astronomy outdoors, but it is not quite as natural to study astronomy during the daytime. This lesson uses the Earth's closest star as a subject of study within the schoolyard. The importance of the rising sun is combined with hands-on inquiry in which students explore the properties of shadows. Students (a) complete a…

  15. Boundary Correct Real-Time Soft Shadows

    DEFF Research Database (Denmark)

    Jacobsen, Bjarke; Christensen, Niels Jørgen; Larsen, Bent Dalgaard

    2004-01-01

    This paper describes a method to determine correct shadow boundaries from an area light source using umbra and penumbra volumes. The light source is approximated by a circular disk as this gives a fast way to extrude the volumes. The method also gives a crude estimate of the visibility of the are...

  16. SHADOW PROCESSES INSTATE BUDGET: CURRENT CONDITION AND DETERMINING FACTORS

    Directory of Open Access Journals (Sweden)

    Z. Varnalii

    2014-12-01

    Full Text Available The most significant factors that move state budget into the shadow are determined. Current condition of shadow processes in state budget is highlighted. The paper also provides an analysis of relationship between political processes and shadow economy in public sector of Ukraine.

  17. SmartShadow models and methods for pervasive computing

    CERN Document Server

    Wu, Zhaohui

    2013-01-01

    SmartShadow: Models and Methods for Pervasive Computing offers a new perspective on pervasive computing with SmartShadow, which is designed to model a user as a personality ""shadow"" and to model pervasive computing environments as user-centric dynamic virtual personal spaces. Just like human beings' shadows in the physical world, it follows people wherever they go, providing them with pervasive services. The model, methods, and software infrastructure for SmartShadow are presented and an application for smart cars is also introduced.  The book can serve as a valuable reference work for resea

  18. Do Elementary Science Methods Textbooks Promote Understanding of Shadows?

    Directory of Open Access Journals (Sweden)

    Lloyd H. Barrow

    2016-02-01

    Full Text Available Elementary science methods textbooks can be an important resource for future elementary teachers of science. Since shadows are a common topic in elementary school and Next Generation Science Standards (NGSS Lead States, 2013. A series of ten shadows concepts were formed into a learning progression by Wizman and Fortus (2007. For this research, ten science methods textbook were read and analyzed about how each of the shadow concepts were addressed. These methods textbooks focused on a limited number of shadow concepts. Consequently, as a future reference, they are very limited in addressing all ten shadow concepts.

  19. Exposing image forgery by detecting consistency of shadow.

    Science.gov (United States)

    Ke, Yongzhen; Qin, Fan; Min, Weidong; Zhang, Guiling

    2014-01-01

    We propose two tampered image detection methods based on consistency of shadow. The first method is based on texture consistency of shadow for the first kind of splicing image, in which the shadow as well as main body is copied and pasted from another image. The suspicious region including shadow and nonshadow is first selected. Then texture features of the shadow region and the nonshadow region are extracted. Last, correlation function is used to measure the similarity of the two texture features. By comparing the similarity, we can judge whether the image is tampered. Due to the failure in detecting the second kind of splicing image, in which main body, its shadow, and surrounding regions are copied and pasted from another image, another method based on strength of light source of shadows is proposed. The two suspicious shadow regions are first selected. Then an efficient method is used to estimate the strength of light source of shadow. Last, the similarity of strength of light source of two shadows is measured by correlation function. By combining the two methods, we can detect forged image with shadows. Experimental results demonstrate that the proposed methods are effective despite using simplified model compared with the existing methods.

  20. Exposing Image Forgery by Detecting Consistency of Shadow

    Directory of Open Access Journals (Sweden)

    Yongzhen Ke

    2014-01-01

    Full Text Available We propose two tampered image detection methods based on consistency of shadow. The first method is based on texture consistency of shadow for the first kind of splicing image, in which the shadow as well as main body is copied and pasted from another image. The suspicious region including shadow and nonshadow is first selected. Then texture features of the shadow region and the nonshadow region are extracted. Last, correlation function is used to measure the similarity of the two texture features. By comparing the similarity, we can judge whether the image is tampered. Due to the failure in detecting the second kind of splicing image, in which main body, its shadow, and surrounding regions are copied and pasted from another image, another method based on strength of light source of shadows is proposed. The two suspicious shadow regions are first selected. Then an efficient method is used to estimate the strength of light source of shadow. Last, the similarity of strength of light source of two shadows is measured by correlation function. By combining the two methods, we can detect forged image with shadows. Experimental results demonstrate that the proposed methods are effective despite using simplified model compared with the existing methods.

  1. FIELD INVESTIGATION OF THE DRIFT SHADOW

    International Nuclear Information System (INIS)

    G.W. Su; T.J. Kneafsey

    2006-01-01

    A drift shadow is an area immediately beneath an underground void that, in theory, will be relatively drier than the surrounding rock mass. Numerical and analytical models of water flow through unsaturated rock predict the existence of a drift shadow, but field tests confirming the existence of the drift shadow have yet to be performed. Proving the existence of drift shadows and understanding their hydrologic and transport characteristics could provide a better understanding of how contaminants move in the subsurface if released from waste emplacement drifts such as the proposed nuclear waste repository at Yucca Mountain, Nevada. We describe the field program that will be used to investigate the existence of a drift shadow--and the corresponding hydrological process at the Hazel-Atlas silica-sand mine located at the Black Diamond Mines Regional Preserve in Antioch, California. The location and configuration of this mine makes it an excellent site to observe and measure drift shadow characteristics. The mine is located in a porous sandstone unit of the Domengine formation, an approximately 230 meter thick series of interbedded Eocene-age shales, coals, and massive-bedded sandstones. The mining method used at the mine required the development of two parallel drifts, one above the other, driven along the strike of the mined sandstone stratum. This configuration provides the opportunity to introduce water into the rock mass in the upper drift and to observe and measure its flow around the underlying drift. The passive and active hydrologic tests to be performed are described. In the passive method, cores will be obtained in a radial pattern around a drift and will be sectioned and analyzed for in-situ water content using a gravimetric technique, as well as analyzed for chemistry. With the active hydrologic test, water will be introduced into the upper drift of the two parallel drifts and the flow of the water will be tracked as it passes near the bottom drift

  2. Effect of Nearshore Islands on Tsunami Inundation in Shadow Zones

    Science.gov (United States)

    Goertz, J.; Kaihatu, J. M.; Kalligeris, N.; Lynett, P. J.; Synolakis, C.

    2017-12-01

    Field surveys performed in the wake of the 2010 Mentawai tsunami event have described the belief of local residents that offshore islands serve as possible tsunami sheltering mechanisms, reducing the corresponding inundation on beaches behind the islands, despite the fact that deduced inundation from debris lines show this to be in fact untrue (Hill et al. 2012). Recent numerical model studies (Stefanakis et al. 2014) have shown that inundation levels on beaches behind conical islands are indeed higher than they are on open coastlines. While work has been done on tsunami amplification on the lee side of islands (Briggs et al. 1995), no work has been done concerning tsunami inundation on beach areas behind the islands. A series of experiments to address this were conducted in the Directional Wave Basin (DWB) at the O.H. Hinsdale Wave Research Laboratory at Oregon State University in summer 2016. A series of four sheet metal islands (two with a full conical section, two truncated at the water line) were placed at varying distances from the toe of a 1/10 sloping beach. Incident wave conditions consisting of solitary waves and full-stroke "dam break" waves were run over the islands. Free surface elevations, velocities, and beach runup were measured, with the intent of determining relationships between the wave condition, the island geometry and distance from the beach, and the tsunami characteristics. A series of runup measurements from a particular set of experiments can be seen in Figure 1. Based on these preliminary analyses, it was determined that: A) inundation was always amplified behind the island relative to areas outside this shadow zone; and B) inundation was generally highest with the island closest to the beach, except in the case where the tsunami wave broke prior to reaching the island. In this latter scenario, the inundation behind the island increased with island distance from the beach. The development of relationships between the inundation levels

  3. Fading and Shadowing in Wireless Systems

    CERN Document Server

    Shankar, P Mohana

    2012-01-01

    In recent decades, growth in the field of wireless communications has led to an exponential rise in the number of journals catering to the research community. Still unmet, however, is the need to fully and comprehensively understand the effects of channel degradation brought on by the statistical fluctuations in the channel. These fluctuations mainly manifest as variations in signal power observed in the channel generally modeled using a variety of probability distributions, both in straight forms as well as in compound forms. While the former might explain some of the effects, it is the latter, namely, the compound models, which incorporate both short term and long term power fluctuations in the channel, explain the much more complex nature of the signals in these channels. Fading and Shadowing in Wireless Systems offers a pedagogical approach to the topic, with insight into the modeling and analysis of fading and shadowing. Beginning with statistical background and digital communications, the book is formul...

  4. Fuzzy split and merge for shadow detection

    Directory of Open Access Journals (Sweden)

    Remya K. Sasi

    2015-03-01

    Full Text Available Presence of shadow in an image often causes problems in computer vision applications such as object recognition and image segmentation. This paper proposes a method to detect the shadow from a single image using fuzzy split and merge approach. Split and merge is a classical algorithm used in image segmentation. Predicate function in the classical approach is replaced by a Fuzzy predicate in the proposed approach. The method follows a top down approach of recursively splitting an image into homogeneous quadtree blocks, followed by a bottom up approach by merging adjacent unique regions. The method has been compared with previous approaches and found to be better in performance in terms of accuracy.

  5. Shadow of rotating wormhole in plasma environment

    Science.gov (United States)

    Abdujabbarov, Ahmadjon; Juraev, Bakhtinur; Ahmedov, Bobomurat; Stuchlík, Zdeněk

    2016-07-01

    The massless particle motion around rotating wormhole in the presence of plasma environment has been studied. It has been shown that the presence of the plasma decreases the inner radius of the circular orbits of photons around rotating wormhole. The shadow cast by rotating wormhole surrounded by inhomogeneous plasma with the radial power-law density has been explored. It has been shown that the shape and size of the wormhole shadow is distorted and changed depending on i) plasma parameters, ii) wormhole rotation and iii) inclination angle between observer plane and axis of rotation of wormhole. As an example we have considered an inverse radial distribution of the plasma density and different types of the wormhole solution.

  6. Jig Aligns Shadow Mask On CCD

    Science.gov (United States)

    Matus, Carlos V.

    1989-01-01

    Alignment viewed through microscope. Alignment jig positions shadow mask on charge-coupled device (CCD) so metal film deposited on it precisely. Allows CCD package to be inserted and removed without disturbing alignment of mask. Holds CCD packages securely and isolates it electrostatically while providing electrical contact to each of its pins. When alignment jig assembled with CCD, used to move mask under micrometer control.

  7. Improving Students' Listening Skill Through Shadowing

    OpenAIRE

    Zuhriyah, Mukminatus

    2016-01-01

    Listening is the first part of language skills that everyone gets when learning a language. It comes before speaking, reading, and writing. Meanwhile, most of the students get difficulty to learn listening of a foreign language, especially English. That is why shadowing was applied in the listening class as one of the solutions to make the learners of English listening easy to understand what the speaker says. This collaborative classroom action research was generally to know whether or not s...

  8. The 'Shadow of Succession' in Family Firms

    OpenAIRE

    Diwisch, Sandra Denise; Voithofer, Peter; Weiss, Christoph

    2005-01-01

    The paper analyses the relationship between succession and firm performance. Using a unique panel data set on a sample of roughly 4,000 Austrian family firms we examine empirically the impact of past succession as well as future succession plans on employment growth and investment behaviour. Analysing succession plans, we do not find a 'shadow of succession' effect. No significant difference in employment growth and investment behaviour is found between firms that plan to transfer the firm in...

  9. Extending the Predictability of Rain Shadow Effects Using Spatial Analogs

    Science.gov (United States)

    Frediani, M. E.; Stull, R.

    2017-12-01

    The goal of this study is to improve forecasts of precipitation and cloudiness over southwest British Columbia, Canada. We investigate the predictability of a Rain Shadow Effect (RSE), characterized by atmospheric states in which the downstream precipitation and associated cloud mass are suppressed as a consequence of flow interaction with orography. When upstream low-level flow is perpendicular to the steep terrain over Vancouver Island, downsloping winds and mountain waves develop over the Strait of Georgia. This condition favors a RSE, characterized by cloudiness and precipitation surrounding the metropolitan Vancouver. The RSE is given by a nonlinear relationship between the atmospheric flow and topography. Consequently, to forecast the RSE, NWP models must correctly predict low-level atmospheric flows, and must accurately represent the region's complex topography. Forecasting the RSE over Vancouver is specifically challenging because of the lack of low-level observations over the eastern Pacific in the so-called Pacific Data Void. The sparse upstream observation network weakens forecast skill normally obtained from data assimilation, and prohibits thorough model verification. Consequently, the atmospheric profile associated with the RSE remains unknown. In this study, analog forecasts are created with a similarity measure based on spatial flow patterns obtained from infrared satellite channels. RSE occurrences are identified using radar reflectivity observations, and the corresponding mesoscale spatial pattern from satellite imagery provide the 2-D flow portrait to search for analogous patterns. This analysis will indicate whether spatial similarities in water vapor and cloudiness flows may be used to detect predictive features and inform probabilities of developing rain shadows over the metropolitan Vancouver region.

  10. Infant Perception of Incongruent Shapes in Cast Shadows

    Directory of Open Access Journals (Sweden)

    Kazuki Sato

    2015-04-01

    Full Text Available A cast shadow occurs when an object blocks the light from an illumination and projects a dark region onto a surface. Previous studies have reported that adults are slower to identify an object when the object has an incongruent cast shadow than when it has a congruent cast shadow (Castiello, 2001. Here, we used the familiarization-novelty preference procedure to examine whether 5- to 8-month-old infants could detect the relationship between object shapes and cast shadows. In Experiment 1, we examined the infants' ability to detect incongruency between objects and cast shadows. Results showed that 7- to 8-month olds could detect incongruence between the object shapes and the cast shadows, whereas 5- to 6-month olds did not. Yet, our control experiment showed that infants could not detect this incongruence from stimuli in which a white outline had been added to the original cast shadow to decrease the possibility of it being perceived as a cast shadow (Experiment 2. The results of these experiments demonstrate that 7- to 8-month olds responded to the congruence of cast shadows and to consistent contrast polarity between the cast shadow and its background.

  11. An Automatic Shadow Detection Method for VHR Remote Sensing Orthoimagery

    Directory of Open Access Journals (Sweden)

    Qiongjie Wang

    2017-05-01

    Full Text Available The application potential of very high resolution (VHR remote sensing imagery has been boosted by recent developments in the data acquisition and processing ability of aerial photogrammetry. However, shadows in images contribute to problems such as incomplete spectral information, lower intensity brightness, and fuzzy boundaries, which seriously affect the efficiency of the image interpretation. In this paper, to address these issues, a simple and automatic method of shadow detection is presented. The proposed method combines the advantages of the property-based and geometric-based methods to automatically detect the shadowed areas in VHR imagery. A geometric model of the scene and the solar position are used to delineate the shadowed and non-shadowed areas in the VHR image. A matting method is then applied to the image to refine the shadow mask. Different types of shadowed aerial orthoimages were used to verify the effectiveness of the proposed shadow detection method, and the results were compared with the results obtained by two state-of-the-art methods. The overall accuracy of the proposed method on the three tests was around 90%, confirming the effectiveness and robustness of the new method for detecting fine shadows, without any human input. The proposed method also performs better in detecting shadows in areas with water than the other two methods.

  12. Field investigation of the drift shadow

    International Nuclear Information System (INIS)

    Su, Grace W.; Kneafsey, Timothy J.; Ghezzehei, Teamrat A.; Marshall, Brian D.; Cook, Paul J.

    2005-01-01

    A drift shadow is an area immediately beneath an underground void that, in theory, will be relatively drier than the surrounding rockmass. Numerical and analytical models of water flow through unsaturated rock predict the existence of a drift shadow, but field tests confirming its existence have yet to be performed. Proving the existence of drift shadows and understanding their hydrologic and transport characteristics could provide a better understanding of how contaminants move in the subsurface if released from waste emplacement drifts such as the proposed nuclear waste repository at Yucca Mountain, Nevada. We describe the field program that will be used to investigate the existence of a drift shadow and the corresponding hydrological process at the Hazel-Atlas silica-sandmine located at the Black Diamond Mines Regional Preserve in Antioch, California. The location and configuration of this mine makes it an excellent site to observe and measure drift shadow characteristics. The mine is located in a porous sandstone unit of the Domengine Formation, an approximately 230 meter thick series of interbedded Eocene-age shales, coals, and massive-bedded sandstones. The mining method used at the mine required the development of two parallel drifts, one above the other, driven along the strike of the mined sandstone stratum. This configuration provides the opportunity to introduce water into the rockmass in the upper drift and to observe and measure its flow around the underlying drift. The passive and active hydrologic tests to be performed are described. In the passive method, cores will be obtained in a radial pattern around a drift and will be sectioned and analyzed for in-situ water content and chemical constituents. With the active hydrologic test, water will be introduced into the upper drift of the two parallel drifts and the flow of the water will be tracked as it passes near the bottom drift. Tensiometers, electrical resistance probes, neutron probes, and ground

  13. Clustered deep shadow maps for integrated polyhedral and volume rendering

    KAUST Repository

    Bornik, Alexander

    2012-01-01

    This paper presents a hardware-accelerated approach for shadow computation in scenes containing both complex volumetric objects and polyhedral models. Our system is the first hardware accelerated complete implementation of deep shadow maps, which unifies the computation of volumetric and geometric shadows. Up to now such unified computation was limited to software-only rendering . Previous hardware accelerated techniques can handle only geometric or only volumetric scenes - both resulting in the loss of important properties of the original concept. Our approach supports interactive rendering of polyhedrally bounded volumetric objects on the GPU based on ray casting. The ray casting can be conveniently used for both the shadow map computation and the rendering. We show how anti-aliased high-quality shadows are feasible in scenes composed of multiple overlapping translucent objects, and how sparse scenes can be handled efficiently using clustered deep shadow maps. © 2012 Springer-Verlag.

  14. PRECONDITIONS AND DETERMINING CAUSES OF THE SHADOW ECONOMY IN UKRAINE

    Directory of Open Access Journals (Sweden)

    Z. Varnalii

    2014-03-01

    Full Text Available The article analyzes the main processes that led to the high level of the economy shadowing. The historical aspects of the formation of the shadow economy in Ukraine are highlighted. The socio-economic aspects of the shadow economy of Ukraine causality are discussed. The theoretical contribution of foreign and domestic researchers on the preconditions of formation of the shadow economy in transition economies is studied. Theoretical perspective on the factors of the shadowing processes in the economy of Ukraine from the standpoint of modern scientific researches is analyzed. The paper also provides scientific vectors for further development of researches aimed at studying the causes and preconditions of the shadow economy.

  15. Corruption and the shadow economy: a structural equation model approach

    OpenAIRE

    Buehn, Andreas; Schneider, Friedrich G.

    2009-01-01

    The relationship between corruption and the shadow economy is not clear. Theoretically, they either substitute or complement each other – exhibiting either a negative or positive relationship. This paper – using a structural equation model with two latent variables – extracts information on various dimensions of corruption and the shadow economy to contribute to the debate on their relationship. It presents empirical evidence of a positive relationship between the shadow economy and corruptio...

  16. How do Institutions Affect Corruption and the Shadow Economy?

    OpenAIRE

    Axel Dreher; Christos Kotsogiannis; Steve McCorriston

    2005-01-01

    This paper analyzes a simple model that captures the relationship between institutional quality, the shadow economy and corruption. It shows that an improvement in institutional quality reduces the shadow economy and affects the corruption market. The exact relationship between corruption and institutional quality is, however, ambiguous and depends on the relative effectiveness of the institutional quality in the shadow and corruption markets. The predictions of the model are empirically test...

  17. A case of shadow flicker/flashing: assessment and solution

    International Nuclear Information System (INIS)

    Clarke, A.D.

    1991-01-01

    A short study was carried out investigating a reported problem of shadow flicker and flashing from the blades of a turbine. The incidence of this phenomenon was confirmed and the duration and frequency of occurrence assessed. The shadow flicker period would be short and only occur at certain times, but could cause irritation. A device to stop the turbine when shadow flicker occurred was recommended and is described. A recommendation was made that turbines should be sited at least ten diameters distance from habitations, and more if sited to the East/Southwest, and the shadow path identified. (author)

  18. Applications of a shadow camera system for energy meteorology

    Science.gov (United States)

    Kuhn, Pascal; Wilbert, Stefan; Prahl, Christoph; Garsche, Dominik; Schüler, David; Haase, Thomas; Ramirez, Lourdes; Zarzalejo, Luis; Meyer, Angela; Blanc, Philippe; Pitz-Paal, Robert

    2018-02-01

    Downward-facing shadow cameras might play a major role in future energy meteorology. Shadow cameras directly image shadows on the ground from an elevated position. They are used to validate other systems (e.g. all-sky imager based nowcasting systems, cloud speed sensors or satellite forecasts) and can potentially provide short term forecasts for solar power plants. Such forecasts are needed for electricity grids with high penetrations of renewable energy and can help to optimize plant operations. In this publication, two key applications of shadow cameras are briefly presented.

  19. In the shadow of their parents

    DEFF Research Database (Denmark)

    Bjerre, Line Søberg

    with the parents. In important ways, their discussions of families are informed by the traditions of social diagnosing, which have historically been informed by psychiatric and psychoanalytic thinking, particularly the notion of psychological determinism; the child’s perspective remains out of sight....... In this tradition, children are largely constructed as passive victims of the parents’ problems. With the child obscured in the shadow of the parents’ social diagnosis, it remains difficult to implement the intentions of legislation that seeks to foreground the child’s perspective. I conclude that if children...

  20. Shadow Banking y Liquidez en Colombia.

    OpenAIRE

    Pamela Cardozo; Jorge Cely; Andrés MUrcia

    2013-01-01

    En este estudio calculamos un indicador de la actividad de shadow banking en Colombia para el período comprendido entre enero de 2011 y marzo de 2013. Dicho indicador sugiere que esta actividad ha venido incrementándose y representa cerca del 9,9% del PIB de 2012. Adicionalmente, evaluamos el nivel de prociclicidad que puede tener la decisión de apalancamiento de un grupo de intermediarios financieros especialmente asociados a este tipo de actividad, encontrando que dicha prociclicidad está a...

  1. Quarkonium plus prompt photon and shadowing extraction

    Energy Technology Data Exchange (ETDEWEB)

    Machado, M.V.T., E-mail: magnus@if.ufrgs.br [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Brenner Mariotto, C., E-mail: mariotto@fisica.furg.br [Instituto de Matematica, Estatistica e Fisica (IMEF). Universidade Federal do Rio Grande (FURG), Rio Grande, RS (Brazil)

    2011-05-15

    In this contribution we investigate the influence of nuclear effects in hadroproduction of quarkonium associated with a photon. At high energies, such processes provide a probe of the QCD dynamics as it is dependent on the nuclear gluon distribution, and could be usefull in constraining the behavior of the nuclear gluon distribution in proton-nucleus and nucleus-nucleus collisions. Here we study the influence of the shadowing effect, in the production of J/{psi}(orY)+{gamma} at the LHC and estimate the p{sub T} dependence of the nuclear modification factors. The theoretical framework considered for quarkonium production is the non-relativistic QCD (NRQCD) factorization formalism.

  2. Control rod shadowing and anti-shadowing effects in a large gas-cooled fast reactor

    International Nuclear Information System (INIS)

    Girardin, G.; Chawla, R.; Rimpault, G.; Coddington, P.

    2007-01-01

    An investigation of control rod shadowing and anti-shadowing (interaction) effects has been carried out in the context of a design study of the control rod pattern for the large 2400 MWth Generation IV Gas-cooled Fast Reactor (GFR). For the calculations, the deterministic code system ERANOS-2.0 has been used, in association with a full core model including a European Fast Reactor (EFR)-type pattern for the control rods. More specifically, the core contains a total of 33 control (CSD) and safety (DSD) rods implemented in three banks: -1) a first bank of 6 CSD rods, placed at 64 cm from core centre in the inner fuel zone (Pu content 16.3 % vol.), -2) a safety bank consisting of 9 DSD rods, at an average distance of 118 cm, and -3) a third bank with 18 CSD rods, placed at 171 cm, i.e. at the interface between the inner and outer (Pu content 19.2 % vol.) core regions. Each control rod has been modelled as a homogeneous material containing 90%-enriched B 4 C, steel and helium. Considerable shadowing effects have been observed between the first bank and the safety bank, as also between individual rods within the first bank. Large anti-shadowing effects take place in an even greater number of the studied rod configurations. The largest interaction is between the two CSD banks, the anti-shadowing value being 46% in this case, implying that the total rod worth is increased by a factor of almost 2 when compared to the sum of the individual bank values. Additional investigations have been performed, in particular the computation of the first order eigenvalue and the eigenvalue separation. The main finding is that the interactions are lower when one of the control rod banks is located at a radial position corresponding to half the core radius. (authors)

  3. Ovarian Basaloid Carcinoma with Shadow Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Michal Zamecnik

    2014-01-01

    Full Text Available So-called shadow cell differentiation (SCD is typical for pilomatrixoma and other skin lesions with follicular differentiation, but it was rarely described also in some visceral carcinomas. We report a case of ovarian basaloid carcinoma with SCD. The tumor presented as a 14 cm ovarian mass in a 45-year-old woman, and therefore the adnexectomy and hysterectomy were performed. The tumor was of high stage. Multiple metastases were found in the liver, retroperitoneal and mediastinal lymph nodes, and the lung. Histologically, the tumor showed a pattern of high-grade basaloid carcinoma with numerous shadow cells. Extensive histologic examination did not reveal any glandular or preexisting teratoma component. Immunohistochemically, the tumor expressed markers of squamous cell differentiation, such as p63, cytokeratin 5/6, and high-molecular-weight keratin. Cytokeratin 7 and CA125 were positive in scattered cells of the lesion. Estrogen and progesterone receptor, vimentin, and p53 were negative. Beta-catenin showed nuclear and cytoplasmic positivity, indicating possible tumor proliferation/differentiation via Wnt signaling pathway. To our knowledge, SCD in basaloid carcinoma of the ovary was not described before. In addition to the description of the case, we review the literature on SCD in visceral carcinomas.

  4. An example of a vector field with the oriented shadowing property

    OpenAIRE

    Tikhomirov, Sergey

    2014-01-01

    We consider shadowing properties for vector fields corresponding to different type of reparametrisations. We give an example of a vector field which has the oriented shadowing properties, but does not have the standard shadowing property.

  5. Shadow Enhancement in Synthetic Aperture Sonar Using Fixed Focusing

    NARCIS (Netherlands)

    Groen, J.; Hansen, R.E.; Callow, H.J.; Sabel, J.C.; Sæbø, T.O.

    2009-01-01

    Abstract—A shadow cast by an object on the seafloor is important information for target recognition in synthetic aperture sonar (SAS) images. Synthetic aperture imaging causes a fundamental limitation to shadow clarity because the illuminator is moved during the data collection. This leads to a

  6. Shading and shadowing on Canaletto's Piazza San Marco

    NARCIS (Netherlands)

    Wijntjes, M.W.A.; De Ridder, H.

    2014-01-01

    Whereas the 17th century painter Canaletto was a master in linear perspective of the architectural elements, he seems to have had considerable difficulty with linear perspective of shadows. A common trick to avoid shadow perspective problems is to set the (solar) illumination direction parallel to

  7. Reusable High Aspect Ratio 3-D Nickel Shadow Mask

    Science.gov (United States)

    Shandhi, M.M.H.; Leber, M.; Hogan, A.; Warren, D.J.; Bhandari, R.; Negi, S.

    2017-01-01

    Shadow Mask technology has been used over the years for resistless patterning and to pattern on unconventional surfaces, fragile substrate and biomaterial. In this work, we are presenting a novel method to fabricate high aspect ratio (15:1) three-dimensional (3D) Nickel (Ni) shadow mask with vertical pattern length and width of 1.2 mm and 40 μm respectively. The Ni shadow mask is 1.5 mm tall and 100 μm wide at the base. The aspect ratio of the shadow mask is 15. Ni shadow mask is mechanically robust and hence easy to handle. It is also reusable and used to pattern the sidewalls of unconventional and complex 3D geometries such as microneedles or neural electrodes (such as the Utah array). The standard Utah array has 100 active sites at the tip of the shaft. Using the proposed high aspect ratio Ni shadow mask, the Utah array can accommodate 300 active sites, 200 of which will be along and around the shaft. The robust Ni shadow mask is fabricated using laser patterning and electroplating techniques. The use of Ni 3D shadow mask will lower the fabrication cost, complexity and time for patterning out-of-plane structures. PMID:29056835

  8. Shadow edge detection using geometric and photometric features

    NARCIS (Netherlands)

    Gijsenij, A.; Gevers, T.

    2009-01-01

    The detection of shadow and shading edges is a first step towards reducing the imaging effects that are caused by interactions of the light source with surfaces that are in the scene. As most of the algorithms for shadow edge detection use photometric information, geometric information have been

  9. Shadows of Einstein–dilaton–Gauss–Bonnet black holes

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Pedro V.P., E-mail: pintodacunha@tecnico.ulisboa.pt [Departamento de Física da Universidade de Aveiro and Centre for Research and Development in Mathematics and Applications (CIDMA), Campus de Santiago, 3810-183 Aveiro (Portugal); CENTRA, Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais 1, 1049, Lisboa (Portugal); Herdeiro, Carlos A.R., E-mail: herdeiro@ua.pt [Departamento de Física da Universidade de Aveiro and Centre for Research and Development in Mathematics and Applications (CIDMA), Campus de Santiago, 3810-183 Aveiro (Portugal); Kleihaus, Burkhard, E-mail: b.kleihaus@uni-oldenburg.de [Institute of Physics, University of Oldenburg, Oldenburg, 26111 (Germany); Kunz, Jutta, E-mail: jutta.kunz@uni-oldenburg.de [Institute of Physics, University of Oldenburg, Oldenburg, 26111 (Germany); Radu, Eugen, E-mail: eugen.radu@ua.pt [Departamento de Física da Universidade de Aveiro and Centre for Research and Development in Mathematics and Applications (CIDMA), Campus de Santiago, 3810-183 Aveiro (Portugal)

    2017-05-10

    We study the shadows of the fully non-linear, asymptotically flat Einstein–dilaton–Gauss–Bonnet (EdGB) black holes (BHs), for both static and rotating solutions. We find that, in all cases, these shadows are smaller than for comparable Kerr BHs, i.e. with the same total mass and angular momentum under similar observation conditions. In order to compare both cases we provide quantitative shadow parameters, observing in particular that the differences in the shadows mean radii are never larger than the percent level. Therefore, generically, EdGB BHs cannot be excluded by (near future) shadow observations alone. On the theoretical side, we find no clear signature of some exotic features of EdGB BHs on the corresponding shadows, such as the regions of negative (Komar, say) energy density outside the horizon. We speculate that this is due to the fact that the Komar energy interior to the light rings (or more precisely, the surfaces of constant radial coordinate that intersect the light rings in the equatorial plane) is always smaller than the ADM mass, and consequently the corresponding shadows are smaller than those of comparable Kerr BHs. The analysis herein provides a clear example that it is the light ring impact parameter, rather than its “size”, that determines a BH shadow.

  10. Study on the Performance of the “Pendulor” Wave Energy Converter in an Array Configuration

    OpenAIRE

    Sudath Prasanna Gunawardane; Chathura Jayan Kankanamge; Tomiji Watabe

    2016-01-01

    For over three decades the “Pendulor” wave energy device has had a significant influence in this field, triggering several research endeavours. It includes a top-hinged flap propelled by the standing waves produced in a caisson with a back wall on the leeward side. However, one of the main disadvantages which impedes its progress is the enormous expense involved in the construction of the custom made typical caisson structure, about a little more than one-quarter of the wave length. In this s...

  11. Damage pattern and damage progression on breakwater roundheads under multidirectional waves

    DEFF Research Database (Denmark)

    Comola, F.; Andersen, Thomas Lykke; Martinelli, L.

    2014-01-01

    An experimental model test study is carried out to investigate damage pattern and progression on a rock armoured breakwater roundhead subjected to multidirectional waves. Concerning damage pattern, the most critical sector is observed to shift leeward with increasing wave period. Taking angles...... over the roundhead is developed. Thus the formula also considers the shifting of the critical sector due to increasing wave period which existing formulae do not include. Finally, analysing the damage produced by double peaked spectra, it is shown that the armour may be designed by the formula when...

  12. Politics, Time and Space in the Era of Shadow Banking

    DEFF Research Database (Denmark)

    Bryan, Dick; Rafferty, Michael; Wigan, Duncan

    2016-01-01

    In the wake of the Global Financial Crisis, there has been an understandable focus on the financial fragility and contagion aspects of shadow banking. This article argues that shadow banking is important for another set of reasons. It has been well established that shadow banking permits...... challenging earlier spatio-temporal concepts of finance, and the regulatory/jurisdictional order built on them. The article suggests that the longer term significance of shadow banking may not just be its role in financial crisis, or even tax and regulatory arbitrage, but that it was here that innovative...... the transformation of assets and financial claims. It has also been established that fiscal and regulatory arbitrage occurs through shadow banking, and associated offshore financial activities. The article develops the argument that together these are transforming the times and spaces of modern finance, and directly...

  13. Simple Impact Crater Shapes From Shadows - The Sequel

    Science.gov (United States)

    Chappelow, J. E.

    2008-12-01

    At the last LPSC meeting I presented the outline of a method for determining simple impact crater shapes from shadows. In theory the shadow cast within a simple crater provides enough information to derive its cross-sectional shape from shadow measurements, at least to the maximum depth to which the shadow extends. Under certain simple assumptions, this can be done analytically. If the crater is conic-section - shaped, then it can be shown that the down-sun bound of any shadow cast within it is elliptical, with one axis along the direction of illumination and the other (perpendicular to it) of semi-length D/2 (where D is diameter). The properties of this shadow-ellipse can be related to the parameters of the crater shape conic-section, thus measurements of the shadow-ellipse yield not only crater depth and diameter but also the approximate crater shape, in terms of conic sections. The method also does not depend upon the shadow crossing near the crater center, which avoids a pitfall of older shadow measurement methods. The technique is also amenable to computer implementation, which has already been largely completed. Once computerized, crater measurements can be made rapidly and repeatably. The program reads in an image, its resolution, and the solar elevation and azimuth. The user then defines the crater rim by 'clicking' on three points, and the shadow ellipse by clicking on two more. The program calculates and outputs the diameter, the depth, and parameters describing the crater's approximating conic-section. It is highly applicable to situations where only single-image photography is available, for example MESSENGER flybys of Mercury. At the meeting I will present the finished math for this method and give some examples of its use.

  14. A BRIEF ANALYSIS OF THE SHADOW ECONOMY IN EUROPE

    Directory of Open Access Journals (Sweden)

    Loredana Maftei

    2013-12-01

    Full Text Available Shadow economy affects all country around the world. European countries are affected by undeclared work, under-reporting and tax evasion. This phenomenon increases from West to East, the most affected being the Balkan area. The size of shadow economy is growing due to government actions, such as regulation and tax implementation. From a macroeconomic perspective, the economic cycle sustain the shadow economy levels. To combat this phenomenon it is necessary to adopt electronic payments, to reduce tax implementations and social contributions, to bring encouragement in cash deposits use and broaden credit cards.

  15. The asymptotic average-shadowing property and transitivity for flows

    International Nuclear Information System (INIS)

    Gu Rongbao

    2009-01-01

    The asymptotic average-shadowing property is introduced for flows and the relationships between this property and transitivity for flows are investigated. It is shown that a flow on a compact metric space is chain transitive if it has positively (or negatively) asymptotic average-shadowing property and a positively (resp. negatively) Lyapunov stable flow is positively (resp. negatively) topologically transitive provided it has positively (resp. negatively) asymptotic average-shadowing property. Furthermore, two conditions for which a flow is a minimal flow are obtained.

  16. Transmit antenna selection based on shadowing side information

    KAUST Repository

    Yilmaz, Ferkan

    2011-05-01

    In this paper, we propose a new transmit antenna selection scheme based on shadowing side information. In the proposed scheme, single transmit antenna which has the highest shadowing coefficient is selected. By the proposed technique, usage of the feedback channel and channel estimation complexity at the receiver can be reduced. We consider independent but not identically distributed Generalized-K composite fading model, which is a general composite fading & shadowing channel model for wireless environments. Exact closed-form outage probability, moment generating function and symbol error probability expressions are derived. In addition, theoretical performance results are validated by Monte Carlo simulations. © 2011 IEEE.

  17. Projected atoll shoreline and run-up changes in response to sea-level rise and varying large wave conditions at Wake and Midway Atolls, Northwestern Hawaiian Islands

    Science.gov (United States)

    Shope, James B.; Storlazzi, Curt; Hoeke, Ron

    2017-01-01

    Atoll islands are dynamic features that respond to seasonal alterations in wave conditions and sea level. It is unclear how shoreline wave run-up and erosion patterns along these low elevation islands will respond to projected sea-level rise (SLR) and changes in wave climate over the next century, hindering communities' preparation for the future. To elucidate how these processes may respond to climate change, extreme boreal winter and summer wave conditions under future sea-level rise (SLR) and wave climate scenarios were simulated at two atolls, Wake and Midway, using a shallow-water hydrodynamic model. Nearshore wave conditions were used to compute the potential longshore sediment flux along island shorelines via the CERC empirical formula and wave-driven erosion was calculated as the divergence of the longshore drift; run-up and the locations where the run-up exceed the berm elevation were also determined. SLR is projected to predominantly drive future island morphological change and flooding. Seaward shorelines (i.e., ocean fronted shorelines directly facing incident wave energy) were projected to experience greater erosion and flooding with SLR and in hypothetical scenarios where changes to deep water wave directions were altered, as informed by previous climate change forced Pacific wave modeling efforts. These changes caused nearshore waves to become more shore-normal, increasing wave attack along previously protected shorelines. With SLR, leeward shorelines (i.e., an ocean facing shoreline but sheltered from incident wave energy) became more accretive on windward islands and marginally more erosive along leeward islands. These shorelines became more accretionary and subject to more flooding with nearshore waves becoming more shore-normal. Lagoon shorelines demonstrated the greatest SLR-driven increase in erosion and run-up. They exhibited the greatest relative change with increasing wave heights where both erosion and run-up magnitudes increased. Wider

  18. Shadow Segmentation and Augmentation Using á-overlay Models that Account for Penumbra

    DEFF Research Database (Denmark)

    Nielsen, Michael; Madsen, Claus B.

    2006-01-01

    This paper introduces a new concept within shadow segmentation. Previously, an image is considered to consist of shadow and non-shadow regions. Thus, a binary mask is estimated using various heuristics regarding structural and retinex/color constancy theories. We wish to model natural shadows so...

  19. Shadow banking in China: expanding scale, evolving structure

    OpenAIRE

    Li, Cindy

    2013-01-01

    This Asia Focus provides an overview of shadow banking activities in China, their close ties with banks, reasons behind their rapid rise, the range of participants and products, and regulatory issues.

  20. Resource-Aware Navigation for Shadowed and Uncertain Environments

    Data.gov (United States)

    National Aeronautics and Space Administration — Discovery of off-Earth ice will transform space exploration. Volatiles that exist primarily in shadowed polar latitudes of planetary bodes could be harvested to...

  1. Testing General Relativity with the Shadow Size of Sgr A(*).

    Science.gov (United States)

    Johannsen, Tim; Broderick, Avery E; Plewa, Philipp M; Chatzopoulos, Sotiris; Doeleman, Sheperd S; Eisenhauer, Frank; Fish, Vincent L; Genzel, Reinhard; Gerhard, Ortwin; Johnson, Michael D

    2016-01-22

    In general relativity, the angular radius of the shadow of a black hole is primarily determined by its mass-to-distance ratio and depends only weakly on its spin and inclination. If general relativity is violated, however, the shadow size may also depend strongly on parametric deviations from the Kerr metric. Based on a reconstructed image of Sagittarius A^{*} (Sgr A^{*}) from a simulated one-day observing run of a seven-station Event Horizon Telescope (EHT) array, we employ a Markov chain Monte Carlo algorithm to demonstrate that such an observation can measure the angular radius of the shadow of Sgr A^{*} with an uncertainty of ∼1.5  μas (6%). We show that existing mass and distance measurements can be improved significantly when combined with upcoming EHT measurements of the shadow size and that tight constraints on potential deviations from the Kerr metric can be obtained.

  2. Physician shadowing by college students: what do patients think?

    OpenAIRE

    Bing-You, Robert G; Hayes, Victoria M; Skolfield, Jennifer L

    2014-01-01

    Background The objective of this study is to determine patients’ perceptions of physician shadowing by college students. Methods Thirty-two patients who agreed to have a college student shadow their physician participated in semi-structured interviews during July and August 2013 at two outpatient family medicine centers. Qualitative techniques were utilized to analyze the transcripts of the patient interviews and identify common themes. Results The majority of patients (78.1%) felt the colleg...

  3. Observation of the moon shadow in deep underground muon flux

    International Nuclear Information System (INIS)

    Allison, W. W. M.; Alner, G. J.; Ayres, D. S.; Cobb, J. H.; Fields, T. H.; Goodman, M. C.; Joffe-Minor, T.; Marshak, M. L.; Price, L. E.; Seidlein, R.; Thron, J. L.

    1999-01-01

    A shadow of the moon, with a statistical significance of 5σ, has been observed in the underground muon flux at a depth of 2090 mwe using the Soudan 2 detector. The angular resolution of the detector is well described by a Gaussian with σ le0.3degree. The position of the shadow confirms the alignment of the detector to better than 0.15degree. This alignment has remained stable during 10 years of data taking from 1989 through 1998

  4. Nuclear shadowing and the optics of hadronic fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Mankiewicz, L. E-mail: lech_mankiewicz@camk.edu.pl; Piller, G.; Vaenttinen, M.; Weise, W

    2001-06-04

    A coordinate-space description of shadowing in deep-inelastic lepton-nucleus scattering is presented. The picture in the laboratory frame is that of quark-gluon fluctuations of the high-energy virtual photon, propagating coherently over large light-cone distances in the nuclear medium. We discuss the detailed dependence of the coherence effects on the invariant mass of the fluctuation. We comment on the issue of possible saturation in the shadowing effects at very small Bjorken-x.

  5. On Risk Charges and Shadow Account Options in Pension Funds

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte; Gatzert, Nadine

    2015-01-01

    to equityholders and our paper develops a model in which the influence of risk charges and shadow account options on stakeholders’ value can be quantified and studied. Our numerical results show that the value of shadow account options can be significant and thus come at the risk of expropriating policyholder...... wealth. However, our analysis also shows that this risk can be remedied if proper attention is given to the specific contract design and to the fixing of fair contract parameters at the outset....

  6. Light - Shadow Interactions in Italian Medieval Churches

    Science.gov (United States)

    Incerti, Manuela

    In the relationship between architecture and the sky, it is possible to identify three different design issues. The first regards the alignment of buildings with visible points on the horizon that coincide with the rising or setting of a celestial body (sun, planets, stars, or moon) on particular dates during the astronomical year (or liturgical year for sacred buildings). The second is the relationship between planimetric design and the design of the elevations. We are all familiar today with several "light effects", which sometimes have almost hierophanic characteristics that, on certain days of the year, were used to engross, captivate, and amaze the spectator. Contrary to the first two issues, the third comes after the design and building stages and concerns the question of decorative elements. It is reasonable to believe that many years after the works were terminated, certain wall finishings were chosen over others, such as painted frescoes or statues. Whoever did this was fully aware, thanks to direct observation, that such decoration would be struck by a single ray of light on a specific day. This chapter examines light-shadow interactions in some Italian medieval churches.

  7. Celestial shadows eclipses, transits, and occultations

    CERN Document Server

    Westfall, John

    2015-01-01

    Much of what is known about the universe comes from the study of celestial shadows—eclipses, transits, and occultations.  The most dramatic are total eclipses of the Sun, which constitute one of the most dramatic and awe-inspiring events of nature.  Though once a source of consternation or dread, solar eclipses now lead thousands of amateur astronomers and eclipse-chasers to travel to remote points on the globe to savor their beauty and the adrenaline-rush of experiencing totality, and were long the only source of information about the hauntingly beautiful chromosphere and corona of the Sun.   Long before Columbus, the curved shadow of the Earth on the Moon during a lunar eclipse revealed that we inhabit a round world. The rare and wonderful transits of Venus, which occur as it passes between the Earth and the Sun, inspired eighteenth century expeditions to measure the distance from the Earth to the Sun, while the recent transits of 2004 and 2012 were the most widely observed ever--and still produced re...

  8. Identification of Methodology of Indirect Assessment of Economy Shadowing

    Directory of Open Access Journals (Sweden)

    Avhustyn Ruslan R.

    2014-03-01

    Full Text Available The article explains the essence of the shadow economy as an objective phenomenon of socio-economic relations and its influence upon national economy security through instruments of pricing, fiscal restrictions, tax control, and banking and insurance regulation. It proves the necessity of use of the indirect method of assessment of the level of economy shadowing along with methods of direct control over the growth of shadowed economic relations, since such an approach would allow rational approach to identification of volumes and level of shadow activity. In the result of the study the article marks out varieties of indirect assessment of economy shadowing (methods of document, accounting and economic analysis, their specific features, advantages and shortcomings and results of practical use. The article reveals approaches and indicators of economic analysis that allow identification of reasons of deviations from the normal economic activity of economic subjects. It provides examples of the indirect method of assessment of the volume of shadowed economy that deal with analysis of demand on money and comparison of rates of the growth of the money supply with the volume of sight drafts with GDP.

  9. Shadows of Kerr Black Holes with Scalar Hair.

    Science.gov (United States)

    Cunha, Pedro V P; Herdeiro, Carlos A R; Radu, Eugen; Rúnarsson, Helgi F

    2015-11-20

    Using backwards ray tracing, we study the shadows of Kerr black holes with scalar hair (KBHSH). KBHSH interpolate continuously between Kerr BHs and boson stars (BSs), so we start by investigating the lensing of light due to BSs. Moving from the weak to the strong gravity region, BSs-which by themselves have no shadows-are classified, according to the lensing produced, as (i) noncompact, which yield not multiple images, (ii) compact, which produce an increasing number of Einstein rings and multiple images of the whole celestial sphere, and (iii) ultracompact, which possess light rings, yielding an infinite number of images with (we conjecture) a self-similar structure. The shadows of KBHSH, for Kerr-like horizons and noncompact BS-like hair, are analogous to, but distinguishable from, those of comparable Kerr BHs. But for non-Kerr-like horizons and ultracompact BS-like hair, the shadows of KBHSH are drastically different: novel shapes arise, sizes are considerably smaller, and multiple shadows of a single BH become possible. Thus, KBHSH provide quantitatively and qualitatively new templates for ongoing (and future) very large baseline interferometry observations of BH shadows, such as those of the Event Horizon Telescope.

  10. THE RESEARCH MATRIX OF POSITIONING THE QUASIGENDER GROUPS AS SHADOW SUBJECTS IN LIMINAL POLITICAL PROCESSES IN RUSSIA

    Directory of Open Access Journals (Sweden)

    Маргарита Витальевна Швец

    2014-05-01

    Full Text Available In the paper a new politological concept of “liminarity” is used in the methological aspect (L.V. Smorgunov, F.A. Shezbukova. It is applied to the situations, when power structures are in the position of losing some ligitimity and the process of legimination of resisting the authorities begins. In these conditions the public political space is actively joined by the actors  with a shadow status, non-public, escaping any contact with the official authoritues.One of such vivid modern examples typical for Russian is quasigender groups (LGBT-community, which appear under liminarity during the transition from the shadow into the public position. They are a modern wave (a second global wave of gender emancipation, which are grounded on their rights’ defense, legalization of their relations (including family in the civil legal field.The author points out approaches to the explanation of the political behavior of quasigender groups, which try to come out of the shadow into the public forms of interpersonal relations.DOI: http://dx.doi.org/10.12731/2218-7405-2013-9-98

  11. Using Shadow Page Cache to Improve Isolated Drivers Performance

    Directory of Open Access Journals (Sweden)

    Hao Zheng

    2015-01-01

    Full Text Available With the advantage of the reusability property of the virtualization technology, users can reuse various types and versions of existing operating systems and drivers in a virtual machine, so as to customize their application environment. In order to prevent users’ virtualization environments being impacted by driver faults in virtual machine, Chariot examines the correctness of driver’s write operations by the method of combining a driver’s write operation capture and a driver’s private access control table. However, this method needs to keep the write permission of shadow page table as read-only, so as to capture isolated driver’s write operations through page faults, which adversely affect the performance of the driver. Based on delaying setting frequently used shadow pages’ write permissions to read-only, this paper proposes an algorithm using shadow page cache to improve the performance of isolated drivers and carefully study the relationship between the performance of drivers and the size of shadow page cache. Experimental results show that, through the shadow page cache, the performance of isolated drivers can be greatly improved without impacting Chariot’s reliability too much.

  12. Using shadow page cache to improve isolated drivers performance.

    Science.gov (United States)

    Zheng, Hao; Dong, Xiaoshe; Wang, Endong; Chen, Baoke; Zhu, Zhengdong; Liu, Chengzhe

    2015-01-01

    With the advantage of the reusability property of the virtualization technology, users can reuse various types and versions of existing operating systems and drivers in a virtual machine, so as to customize their application environment. In order to prevent users' virtualization environments being impacted by driver faults in virtual machine, Chariot examines the correctness of driver's write operations by the method of combining a driver's write operation capture and a driver's private access control table. However, this method needs to keep the write permission of shadow page table as read-only, so as to capture isolated driver's write operations through page faults, which adversely affect the performance of the driver. Based on delaying setting frequently used shadow pages' write permissions to read-only, this paper proposes an algorithm using shadow page cache to improve the performance of isolated drivers and carefully study the relationship between the performance of drivers and the size of shadow page cache. Experimental results show that, through the shadow page cache, the performance of isolated drivers can be greatly improved without impacting Chariot's reliability too much.

  13. eShadow: A tool for comparing closely related sequences

    Energy Technology Data Exchange (ETDEWEB)

    Ovcharenko, Ivan; Boffelli, Dario; Loots, Gabriela G.

    2004-01-15

    Primate sequence comparisons are difficult to interpret due to the high degree of sequence similarity shared between such closely related species. Recently, a novel method, phylogenetic shadowing, has been pioneered for predicting functional elements in the human genome through the analysis of multiple primate sequence alignments. We have expanded this theoretical approach to create a computational tool, eShadow, for the identification of elements under selective pressure in multiple sequence alignments of closely related genomes, such as in comparisons of human to primate or mouse to rat DNA. This tool integrates two different statistical methods and allows for the dynamic visualization of the resulting conservation profile. eShadow also includes a versatile optimization module capable of training the underlying Hidden Markov Model to differentially predict functional sequences. This module grants the tool high flexibility in the analysis of multiple sequence alignments and in comparing sequences with different divergence rates. Here, we describe the eShadow comparative tool and its potential uses for analyzing both multiple nucleotide and protein alignments to predict putative functional elements. The eShadow tool is publicly available at http://eshadow.dcode.org/

  14. A separable shadow Hamiltonian hybrid Monte Carlo method

    Science.gov (United States)

    Sweet, Christopher R.; Hampton, Scott S.; Skeel, Robert D.; Izaguirre, Jesús A.

    2009-11-01

    Hybrid Monte Carlo (HMC) is a rigorous sampling method that uses molecular dynamics (MD) as a global Monte Carlo move. The acceptance rate of HMC decays exponentially with system size. The shadow hybrid Monte Carlo (SHMC) was previously introduced to reduce this performance degradation by sampling instead from the shadow Hamiltonian defined for MD when using a symplectic integrator. SHMC's performance is limited by the need to generate momenta for the MD step from a nonseparable shadow Hamiltonian. We introduce the separable shadow Hamiltonian hybrid Monte Carlo (S2HMC) method based on a formulation of the leapfrog/Verlet integrator that corresponds to a separable shadow Hamiltonian, which allows efficient generation of momenta. S2HMC gives the acceptance rate of a fourth order integrator at the cost of a second-order integrator. Through numerical experiments we show that S2HMC consistently gives a speedup greater than two over HMC for systems with more than 4000 atoms for the same variance. By comparison, SHMC gave a maximum speedup of only 1.6 over HMC. S2HMC has the additional advantage of not requiring any user parameters beyond those of HMC. S2HMC is available in the program PROTOMOL 2.1. A Python version, adequate for didactic purposes, is also in MDL (http://mdlab.sourceforge.net/s2hmc).

  15. The interrupted power law and the size of shadow banking.

    Science.gov (United States)

    Fiaschi, Davide; Kondor, Imre; Marsili, Matteo; Volpati, Valerio

    2014-01-01

    Using public data (Forbes Global 2000) we show that the asset sizes for the largest global firms follow a Pareto distribution in an intermediate range, that is "interrupted" by a sharp cut-off in its upper tail, where it is totally dominated by financial firms. This flattening of the distribution contrasts with a large body of empirical literature which finds a Pareto distribution for firm sizes both across countries and over time. Pareto distributions are generally traced back to a mechanism of proportional random growth, based on a regime of constant returns to scale. This makes our findings of an "interrupted" Pareto distribution all the more puzzling, because we provide evidence that financial firms in our sample should operate in such a regime. We claim that the missing mass from the upper tail of the asset size distribution is a consequence of shadow banking activity and that it provides an (upper) estimate of the size of the shadow banking system. This estimate-which we propose as a shadow banking index-compares well with estimates of the Financial Stability Board until 2009, but it shows a sharper rise in shadow banking activity after 2010. Finally, we propose a proportional random growth model that reproduces the observed distribution, thereby providing a quantitative estimate of the intensity of shadow banking activity.

  16. Abnormal chest shadow on CT in immunosuppressed patients

    International Nuclear Information System (INIS)

    Tanaka, Nobuyuki; Matsumoto, Tsuneo; Nakamura, Hiroshi

    1992-01-01

    An abnormal chest shadow was observed on CT scans in 25 cases of 23 immunosuppressed patients. Pulmonary disease was pathologically confirmed to be pneumocystis carinii pneumonia (PC pneumonia) in four patients, cytomegalovirus pneumonia (CMV pneumonia) in one, bacterial pneumonia in seven, fungal infection in three, miliary tuberculosis in one, leukemic infiltration in two, lymphangitis carcinomatosa in three, drug-induced pneumonitis in three, and ARDS in one. In almost all patients, especially those with infectious diseases such as PC pneumonia, CMV pneumonia, and bacterial pneumonia, the abnormal shadow was wide and visible in the bilateral lung fields. We presumed that such findings as lobular shadow, centrilobular shadow, and mosaic pattern reflected the extension of disease via the respiratory tract, and that those findings are typical of infectious diseases. Because such findings as abnormal linear shadow and swelling of a broncho-vascular bundle were very frequently recognized in patients with lymphangitis carcinomatosa and frequently recognized in those with drug-induced pneumonitis, these diseases may be distinguished from other diseases. An area of slightly increased density was frequently recognized in patients with PC pneumonia, bacterial pneumonia, and drug-induced pneumonitis. Such lesions were pathologically confirmed to be located in the interstitium and/or alveolus. CT was extremely useful in comprehending the character and extension of particular diseases among various diseases. As the number of patients studied was small, the utility of CT in immunosuppressed patients requires further investigation in a larger number of patients. (author)

  17. The Dark Shadow of Virtual Reality

    Directory of Open Access Journals (Sweden)

    Claire Su-Yeon Park

    2018-01-01

    Full Text Available Virtual Reality (VR technology are entering nursing education at a rapid speed (Foronda et al., 2017. VR has been reported in the nursing literature to significantly improve students’ performance (Jenson & Forsyth, 2012; Park, 2016; Foronda et al., 2017 even though the body of evidence in terms of the number and research quality of peer reviewed research papers is not yet substantial enough to identify VR technology’s effectiveness. However, VR is not actually reality. VR may not actually reflect reality. Young people (and even adults may not perceive the different between reality and VR. They may not yet be mature enough to distinguish the difference. However, VR technology are going much further than traditional educational methods by allowing humans to experience a much higher level of immersion through a virtual image. Even the gap between advances in VR technology and its application to education science is widening, causing serious concern. The advance in VR technology is value-neutral. As with all things, whether something is good or bad depends on how humans use it. VR can be useful, for example, when it enables scholars to attend an international conference without traveling to the physical convention center. VR provides the ability to speak, listen, and discuss in real time. Those using VR can choose to view a featured or real-time image of the other participants as if they were actually at the conference. Further, remote participants can feel touch through electronic sensors attached to their body. How amazing! The problem with VR lies in the fact that we are not ready to cope with any possible harmful influences caused by advances in VR technology. But what is the “Dark Shadow of VR,” and why does it cause concern, particularly in pedagogy? Luc Besson’s 2017 film Valerian and the City of a Thousand Plants showed an exceptional VR world, “Big Market,” a shopping-focused VR platform. But such a world is no longer strictly

  18. Multiple shooting shadowing for sensitivity analysis of chaotic dynamical systems

    Science.gov (United States)

    Blonigan, Patrick J.; Wang, Qiqi

    2018-02-01

    Sensitivity analysis methods are important tools for research and design with simulations. Many important simulations exhibit chaotic dynamics, including scale-resolving turbulent fluid flow simulations. Unfortunately, conventional sensitivity analysis methods are unable to compute useful gradient information for long-time-averaged quantities in chaotic dynamical systems. Sensitivity analysis with least squares shadowing (LSS) can compute useful gradient information for a number of chaotic systems, including simulations of chaotic vortex shedding and homogeneous isotropic turbulence. However, this gradient information comes at a very high computational cost. This paper presents multiple shooting shadowing (MSS), a more computationally efficient shadowing approach than the original LSS approach. Through an analysis of the convergence rate of MSS, it is shown that MSS can have lower memory usage and run time than LSS.

  19. Ferromagnetic shadow mask for spray coating of polymer patterns

    DEFF Research Database (Denmark)

    Keller, Stephan Sylvest; Bosco, Filippo; Boisen, Anja

    2013-01-01

    We present the fabrication of a wafer-scale shadow mask with arrays of circular holes with diameters of 150–400 μm. Standard UV photolithography is used to define 700 μm thick SU-8 structures followed by electroplating of nickel and etching of the template. The ferromagnetic properties of the sha......We present the fabrication of a wafer-scale shadow mask with arrays of circular holes with diameters of 150–400 μm. Standard UV photolithography is used to define 700 μm thick SU-8 structures followed by electroplating of nickel and etching of the template. The ferromagnetic properties...... of the shadow mask allow magnetic clamping to the substrate and spray coating of well defined polymer patterns....

  20. Shadow corrosion evaluation in the Studsvik R2 reactor

    International Nuclear Information System (INIS)

    Sanders, Ch.; Lysell, G.

    2000-01-01

    Post-irradiation examination has shown that increased corrosion occurs when zirconium alloys are in contact with or in proximity to other metallic objects. The observations indicate an influence of irradiation from the adjacent component as the enhanced corrosion occurs as a 'shadow' of the metallic object on the zirconium surface. This phenomenon could ultimately limit the lifetime of certain zirconium alloy components in the reactor. The Studsvik R2 materials test reactor has an In-Core Autoclave (INCA) test facility especially designed for water chemistry and materials research. The INCA facility has been evaluated and found suitable for shadow corrosion studies. The R2 reactor core containing the INCA facility was modeled with the Monte Carlo N-Particle (MCNP) code in order to evaluate the electron deposition in various materials and to develop a hypothesis of the shadow corrosion mechanism. (authors)

  1. Medium Access Control for Opportunistic Concurrent Transmissions under Shadowing Channels

    Directory of Open Access Journals (Sweden)

    Seung Min Hur

    2009-06-01

    Full Text Available We study the problem of how to alleviate the exposed terminal effect in multihop wireless networks in the presence of log-normal shadowing channels. Assuming node location information, we propose an extension of the IEEE 802.11 MAC protocol that schedules concurrent transmissions in the presence of log-normal shadowing, thus mitigating the exposed terminal problem and improving network throughput and delay performance. We observe considerable improvements in throughput and delay achieved over the IEEE 802.11 MAC under various network topologies and channel conditions in ns-2 simulations, which justify the importance of considering channel randomness in MAC protocol design for multihop wireless networks.

  2. Tracking the Shadows through GMRT D. Narasimha , N. Kanekar ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Tracking the Shadows through GMRT. D. Narasimha. 1. , N. Kanekar. 2. & J. N. Chengalur. 2. 1Tata Institute of Fundamental Research, Mumbai 400 005. 2NCRA, Tata Institute of Fundamental Research, Pune 411 007. Abstract. The structures of faint high redshift galaxies cannot be observed directly. But if a luminous ...

  3. Shadow Formation at Preschool from a Socio-materiality Perspective

    Science.gov (United States)

    Impedovo, Maria Antonietta; Delserieys-Pedregosa, Alice; Jégou, Corinne; Ravanis, Konstantinos

    2017-06-01

    The paper is set in socio-material farming to offer a way of conceptualising actions and interactions of children in preschool involved in the understanding of scientific concepts. A model of early science education about the physical phenomena of shadow formation is implemented in group work in a French context. The research involved 44 children (13 females and 31 males) of 5-6 years old. The research design was organised in three video recording steps: pre-test, teaching session and post-test. We focus on the analysis of nine teaching sessions to investigate children's `understanding' of shadow formation. A descriptive and qualitative approach was used. In particular, we have identified three main categories (the interaction of the children with the tools, the embodiment and verbal dimension)—with respective indicators—to perform the analysis. From the results, all the categories explored seem to influence each other: all material, human and social dimensions contribute to the children's understanding of shadow formation. Also we have identified some elements that can serve as a potential source of improvement of the teaching session on shadow formation. Finally, the research provides insights on how to improve science activities in preschool with the aim of supporting early understanding of physical phenomena.

  4. Estimating Outdoor Illumination Conditions Based on Detection of Dynamic Shadows

    DEFF Research Database (Denmark)

    Madsen, Claus B.; Lal, Brajesh Behari

    2013-01-01

    into the image stream to achieve realistic Augmented Reality where the shading and the shadowing of virtual objects is consistent with the real scene. Other techniques require the presence of a known object, a light probe, in the scene for estimating illumination. The technique proposed here works in general...

  5. Three-Dimensional Reconstruction Optical System Using Shadows Triangulation

    Science.gov (United States)

    Barba, J. Leiner; Vargas, Q. Lorena; Torres, M. Cesar; Mattos, V. Lorenzo

    2008-04-01

    In this work is developed a three-dimensional reconstruction system using the Shades3D tool of the Matlab® Programming Language and materials of low cost, such as webcam camera, a stick, a weak structured lighting system composed by a desk lamp, and observation plane in which the object is located. The reconstruction is obtained through a triangulation process that is executed after acquiring a sequence of images of the scene with a shadow projected on the object; additionally an image filtering process is done for obtaining only the part of the scene that will be reconstructed. Previously, it is necessary to develop a calibration process for determining the internal camera geometric and optical characteristics (intrinsic parameters), and the 3D position and orientation of the camera frame relative to a certain world coordinate system (extrinsic parameters). The lamp and the stick are used to produce a shadow which scans the object; in this technique, it is not necessary to know the position of the light source, instead the triangulation is obtained using shadow plane produced by intersection between the stick and the illumination pattern. The webcam camera captures all images with the shadow scanning the object, and Shades3D tool processes all information taking into account captured images and calibration parameters. Likewise, this technique is evaluated in the reconstruction of parts of the human body and its application in the detection of external abnormalities and elaboration of prosthesis or implant.

  6. Physician shadowing by college students: what do patients think?

    Science.gov (United States)

    Bing-You, Robert G; Hayes, Victoria M; Skolfield, Jennifer L

    2014-03-14

    The objective of this study is to determine patients' perceptions of physician shadowing by college students. Thirty-two patients who agreed to have a college student shadow their physician participated in semi-structured interviews during July and August 2013 at two outpatient family medicine centers. Qualitative techniques were utilized to analyze the transcripts of the patient interviews and identify common themes. The majority of patients (78.1%) felt the college student had a neutral effect on their visit and denied having concerns about confidentiality (87.5%). No patient felt that having the college student present affected their ability to maintain a trusting relationship with their physician. Three themes emerged from the qualitative analysis: benefits to students, willing participation and sensitive issues. Most patients (78.5%) recognized that the student was in college or was a premedical student. The overwhelming majority of patients stated that they would have a college student shadow their physician again in the future. Despite concerns raised by other authors about the possible negative effects of physician shadowing by college students, this study shows that patients feel the impact to be primarily neutral and that there are many perceived benefits to both student and patient.

  7. Shadow Capital: The Democratization of College Preparatory Education

    Science.gov (United States)

    Cipollone, Kristin; Stich, Amy E.

    2017-01-01

    In this article, we examine the manifestation and consequences of shadow capital within two public, urban, nonselective, college preparatory-designated high schools serving exclusively nondominant students. Informed by three years of ethnographic data, we argue that the transference of a historically elite college preparatory education from…

  8. On Risk Charges and Shadow Account Options in Pension Funds

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte; Gatzert, Nadine

    This paper studies the economic implications of regulatory systems which allow equityholders of pension companies to not only charge a specific premium to compensate them for their higher risk (compared to policyholders), but also to accumulate these risk charges in a so-called shadow account in ...

  9. Assessment of multipath and shadowing effects on UHF band in ...

    African Journals Online (AJOL)

    In this work, the multi-path and shadowing effects on signal impairment were investigated through the use of empirical and semi-empirical path loss models analysis in built-up environments. Electromagnetic field strength measurements were conducted using four television transmitters at UHF bands along four major routes ...

  10. Perspective: Dynamic Shadowing Growth and its Energy Applications

    Directory of Open Access Journals (Sweden)

    Yiping eZhao

    2014-09-01

    Full Text Available The unique features of dynamic shadowing growth (DSG in structural and compositional design of nanomaterials are discussed. Their recent applications in energy storage, fuel cell, and solar energy conversion have been reviewed briefly. Future directions for applying DSG nanostructures in renewable energy applications are presented.

  11. EFFECT OF SHADOWING AND MULTIPATH FADING ON THE ...

    African Journals Online (AJOL)

    irrespective of their location. The traditional macro-only network have been proved ineffective when communication signal is required for users located in the cell edge and a certain distance away from the macrocell base station. This is because of excess attenuation of the signal due to fading and shadowing. Multipath ...

  12. Wake models developed during the Wind Shadow Project

    DEFF Research Database (Denmark)

    Larsen, Søren Ejling; Ott, Søren; Pena Diaz, Alfredo

    The Wind Shadow project has developed and validated improved models for determining the wakes losses, and thereby the array efficiency of very large, closely packed wind farms. The rationale behind the project has been that the existing software has been covering these types of wind farms poorly...

  13. Infrasound propagation in tropospheric ducts and acoustic shadow zones.

    Science.gov (United States)

    de Groot-Hedlin, Catherine D

    2017-10-01

    Numerical computations of the Navier-Stokes equations governing acoustic propagation are performed to investigate infrasound propagation in the troposphere and into acoustic shadow zones. An existing nonlinear finite-difference, time-domain (FDTD) solver that constrains input sound speed models to be axisymmetric is expanded to allow for advection and rigid, stair-step topography. The FDTD solver permits realistic computations along a given azimuth. It is applied to several environmental models to examine the effects of nonlinearity, topography, advection, and two-dimensional (2D) variations in wind and sound speeds on the penetration of infrasound into shadow zones. Synthesized waveforms are compared to a recording of a rocket motor fuel elimination event at the Utah Test and Training Range. Results show good agreement in the amplitude, duration, and spectra of synthesized and recorded waveforms for propagation through 2D atmospheric models whether or not topography, advection, or nonlinearity is explicitly included. However, infrasound propagation through a one-dimensional, range-averaged, atmospheric model yields waveforms with lower amplitudes and frequencies, suggesting that small-scale atmospheric variability causes significant scatter within the troposphere, leading to enhanced infrasound penetration into shadow zones. Thus, unresolved fine-scale atmospheric dynamics are not required to explain infrasound propagation into shadow zones.

  14. Shadow-Based Vehicle Detection in Urban Traffic

    Directory of Open Access Journals (Sweden)

    Manuel Ibarra-Arenado

    2017-04-01

    Full Text Available Vehicle detection is a fundamental task in Forward Collision Avoiding Systems (FACS. Generally, vision-based vehicle detection methods consist of two stages: hypotheses generation and hypotheses verification. In this paper, we focus on the former, presenting a feature-based method for on-road vehicle detection in urban traffic. Hypotheses for vehicle candidates are generated according to the shadow under the vehicles by comparing pixel properties across the vertical intensity gradients caused by shadows on the road, and followed by intensity thresholding and morphological discrimination. Unlike methods that identify the shadow under a vehicle as a road region with intensity smaller than a coarse lower bound of the intensity for road, the thresholding strategy we propose determines a coarse upper bound of the intensity for shadow which reduces false positives rates. The experimental results are promising in terms of detection performance and robustness in day time under different weather conditions and cluttered scenarios to enable validation for the first stage of a complete FACS.

  15. Seri Rama: converting a shadow play puppet to Street Fighter.

    Science.gov (United States)

    Ghani, D B A

    2012-01-01

    Shadow puppet plays, a traditional Malaysian theater art, is slowly losing its appeal to adolescents, who prefer computer games. To help reverse this decline, the authors incorporated the traditional Seri Rama character into the Street Fighter video game. Using modeling, texturing, and animation, they developed a 3D Seri Rama prototype. Users can control Seri Rama with a PlayStation game controller.

  16. Shadowing: Who Benefits and How? Uncovering a Booming EFL Teaching Technique for Listening Comprehension

    Science.gov (United States)

    Hamada, Yo

    2016-01-01

    This study examines common claims associated with shadowing. Studies in Japan conclude that shadowing is effective for improving learners' listening skills. Two common claims are that shadowing is effective for lower-proficiency learners and that it enhances learners' phoneme perception, thus improving listening comprehension skills. The former…

  17. The Shadow Knows: Using Shadows to Investigate the Structure of the Pretransitional Disk of HD 100453

    Energy Technology Data Exchange (ETDEWEB)

    Long, Zachary C.; Fernandes, Rachel B.; Sitko, Michael [Department of Physics, University of Cincinnati, Cincinnati, OH 45221 (United States); Wagner, Kevin [Department of Astronomy/Steward Observatory, The University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Muto, Takayuki [Division of Liberal Arts, Kogakuin University, 1-24-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo, 163-8677 (Japan); Hashimoto, Jun; Oh, Daehyon; Tamura, Motohide; Yang, Yi [National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo, 181-8588 (Japan); Follette, Katherine [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Grady, Carol A. [Eureka Scientific, 2452 Delmer Street, Suite 100, Oakland CA 96402 (United States); Fukagawa, Misato [Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Nagoya (Japan); Hasegawa, Yasuhiro [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Kluska, Jacques; Kraus, Stefan [University of Exeter Astrophysics Group, School of Physics, Stocker Road, Exeter, Devon EX4 4QL (United Kingdom); Mayama, Satoshi [Department of Astronomical Science, The Graduate University for Advanced Studies (SOKENDAI), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); McElwain, Michael W. [Exoplanets and Stellar Astrophysics Laboratory, Code 667, NASA’s Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Uyama, Taichi [Department of Astronomy and RESCUE, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan); Wisniewski, John P. [Homer L. Dodge Department of Physics, University of Oklahoma, Norman, OK 73071 (United States)

    2017-03-20

    We present Gemini Planet Imager polarized intensity imagery of HD 100453 in Y , J , and K 1 bands that reveals an inner gap (9–18 au), an outer disk (18–39 au) with two prominent spiral arms, and two azimuthally localized dark features that are also present in Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) total intensity images. Spectral energy distribution fitting further suggests that the radial gap extends to 1 au. The narrow, wedge-like shape of the dark features appears similar to predictions of shadows cast by an inner disk that is misaligned with respect to the outer disk. Using the Monte Carlo radiative transfer code HOCHUNCK3D, we construct a model of the disk that allows us to determine its physical properties in more detail. From the angular separation of the features, we measure the difference in inclination between the disks (45°) and their major axes, PA = 140° east of north for the outer disk, and 100° for the inner disk. We find an outer-disk inclination of 25° ± 10° from face-on, in broad agreement with the Wagner et al. measurement of 34°. SPHERE data in J and H bands indicate a reddish disk, which indicates that HD 100453 is evolving into a young debris disk.

  18. Shallow water sound propagation with surface waves.

    Science.gov (United States)

    Tindle, Chris T; Deane, Grant B

    2005-05-01

    The theory of wavefront modeling in underwater acoustics is extended to allow rapid range dependence of the boundaries such as occurs in shallow water with surface waves. The theory allows for multiple reflections at surface and bottom as well as focusing and defocusing due to reflection from surface waves. The phase and amplitude of the field are calculated directly and used to model pulse propagation in the time domain. Pulse waveforms are obtained directly for all wavefront arrivals including both insonified and shadow regions near caustics. Calculated waveforms agree well with a reference solution and data obtained in a near-shore shallow water experiment with surface waves over a sloping bottom.

  19. A Soft Shadow Detection Method Based on MRF for Remote Sensing Images

    Directory of Open Access Journals (Sweden)

    Pengwei Li

    2015-01-01

    Full Text Available Shadows limit many remote sensing applications such as classification, target detection, and change detection. Most current shadow detection methods utilize the histogram threshold of spectral characteristics to distinguish the shadows and nonshadows directly, called “hard binary shadow.” Obviously, the performance of threshold-based methods heavily rely on the selected threshold. Simultaneously, these threshold-based methods do not take any spatial information into account. To overcome these shortcomings, a soft shadow description method is developed by introducing the concept of opacity into shadow detection, and MRF-based shadow detection method is proposed in order to make use of neighborhood information. Experiments on remote sensing images have shown that the proposed method can obtain more accurate detection results.

  20. Determinants of the Shadow Economy in the Czech Regions: A Region-Level Study

    Directory of Open Access Journals (Sweden)

    Buček Jakub

    2017-09-01

    Full Text Available This paper investigates the size and development of the shadow economy in the Czech Republic on the state-level base over the 2005-2014 period. The multiple indicators multiple causes (MIMIC model is used to assess the estimation of the shadow economy size. I investigate how labour market, number of people with at least one distraint, and the burden of taxation might contribute to the existence of the shadow economy. While the former two are important determinants of the shadow economy, I find no evidence to prove any significant impact of distraints on the shadow economy size. As for the country’s particular regions, I find that those surrounding big cities, especially Prague, have, on average, a smaller shadow economy size, whereas regions in the borderlands (former Sudetenland suffer from a larger shadow economy.

  1. Shadow casted by a Konoplya-Zhidenko rotating non-Kerr black hole

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Mingzhi; Chen, Songbai; Jing, Jiliang, E-mail: wmz9085@126.com, E-mail: csb3752@hunnu.edu.cn, E-mail: jljing@hunnu.edu.cn [Institute of Physics and Department of Physics, Hunan Normal University, Changsha, Hunan 410081 (China)

    2017-10-01

    We have investigated the shadow of a Konoplya-Zhidenko rotating non-Kerr black hole with an extra deformation parameter. The spacetime structure arising from the deformed parameter affects sharply the black hole shadow. With the increase of the deformation parameter, the size of the shadow of black hole increase and its shape becomes more rounded for arbitrary rotation parameter. The D-shape shadow of black hole emerges only in the case a <2√3/3\\, M with the proper deformation parameter. Especially, the black hole shadow possesses a cusp shape with small eye lashes in the cases with a >M, and the shadow becomes less cuspidal with the increase of the deformation parameter. Our result show that the presence of the deformation parameter yields a series of significant patterns for the shadow casted by a Konoplya-Zhidenko rotating non-Kerr black hole.

  2. Riddles in the Dark: Imaging Inside Mercury's Permanently Shadowed Craters

    Science.gov (United States)

    Ernst, C. M.; Chabot, N. L.; Denevi, B. W.; Nair, H.; Deutsch, A. N.; Murchie, S. L.; Robinson, M. S.; Blewett, D. T.; Head, J. W.; Harmon, J. K.; Neumann, G. A.; Solomon, S. C.

    2013-12-01

    Numerous lines of evidence independently point to the presence of water ice in Mercury's polar regions: Earth-based radar shows radar-bright regions; Mariner 10 and MESSENGER Mercury Dual Imaging System (MDIS) images reveal that these regions are permanently (south polar region) or persistently (north polar region) shadowed; neutron spectrometry indicates hydrogen-rich material; thermal models support the presence of water ice; and Mercury Laser Altimeter (MLA) reflectance measurements at 1064 nm show high and low reflectance deposits consistent in location to where models predict surface and buried water ice, respectively. Throughout 2013, MESSENGER executed a campaign dedicated to imaging the permanently shadowed crater floors of Mercury's north polar region using sunlight scattered from nearby terrain. The campaign makes use of the broadband clear filter (central wavelength 700 nm, bandwidth 600 nm) of the MDIS wide-angle camera (WAC) to target and image radar-bright areas within all host craters > 10 km in diameter under multiple lighting conditions. To date, MESSENGER has imaged the interiors of nearly 20 craters that host radar-bright deposits, including the largest such deposits near the north pole that are likely to host surface water ice. The images reveal a variety of surface morphologies, ranging from the smooth crater floor of the fresh Kandinsky crater, to the moderately cratered floor of Tolkien crater, and to the battered floor of Prokofiev crater, in which the permanently shadowed region does not differ morphologically from the rest of the crater floor. Thus, no distinct morphology is identified in association with polar deposits, and craters hosting such material span the typical range of degradation states relative to their illuminated counterparts. MDIS images also reveal albedo differences in craters with floors not fully in permanent shadow. Prokofiev provides a special environment for viewing a radar- and MLA-bright region suspected to host

  3. Shadows and spirals in the protoplanetary disk HD 100453

    Science.gov (United States)

    Benisty, M.; Stolker, T.; Pohl, A.; de Boer, J.; Lesur, G.; Dominik, C.; Dullemond, C. P.; Langlois, M.; Min, M.; Wagner, K.; Henning, T.; Juhasz, A.; Pinilla, P.; Facchini, S.; Apai, D.; van Boekel, R.; Garufi, A.; Ginski, C.; Ménard, F.; Pinte, C.; Quanz, S. P.; Zurlo, A.; Boccaletti, A.; Bonnefoy, M.; Beuzit, J. L.; Chauvin, G.; Cudel, M.; Desidera, S.; Feldt, M.; Fontanive, C.; Gratton, R.; Kasper, M.; Lagrange, A.-M.; LeCoroller, H.; Mouillet, D.; Mesa, D.; Sissa, E.; Vigan, A.; Antichi, J.; Buey, T.; Fusco, T.; Gisler, D.; Llored, M.; Magnard, Y.; Moeller-Nilsson, O.; Pragt, J.; Roelfsema, R.; Sauvage, J.-F.; Wildi, F.

    2017-01-01

    Context. Understanding the diversity of planets requires studying the morphology and physical conditions in the protoplanetary disks in which they form. Aims: We aim to study the structure of the 10 Myr old protoplanetary disk HD 100453, to detect features that can trace disk evolution and to understand the mechanisms that drive these features. Methods: We observed HD 100453 in polarized scattered light with VLT/SPHERE at optical (0.6 μm, 0.8 μm) and near-infrared (1.2 μm) wavelengths, reaching an angular resolution of 0.02'', and an inner working angle of 0.09''. Results: We spatially resolve the disk around HD 100453, and detect polarized scattered light up to 0.42'' ( 48 au). We detect a cavity, a rim with azimuthal brightness variations at an inclination of 38° with respect to our line of sight, two shadows and two symmetric spiral arms. The spiral arms originate near the location of the shadows, close to the semi major axis. We detect a faint feature in the SW that can be interpreted as the scattering surface of the bottom side of the disk, if the disk is tidally truncated by the M-dwarf companion currently seen at a projected distance of 119 au. We construct a radiative transfer model that accounts for the main characteristics of the features with an inner and outer disk misaligned by 72°. The azimuthal brightness variations along the rim are well reproduced with the scattering phase function of the model. While spirals can be triggered by the tidal interaction with the companion, the close proximity of the spirals to the shadows suggests that the shadows could also play a role. The change in stellar illumination along the rim induces an azimuthal variation of the scale height that can contribute to the brightness variations. Conclusions: Dark regions in polarized images of transition disks are now detected in a handful of disks and often interpreted as shadows due to a misaligned inner disk. However, the origin of such a misalignment in HD 100453, and

  4. Valuing ecosystem services. A shadow price for net primary production

    International Nuclear Information System (INIS)

    Richmond, Amy; Kaufmann, Robert K.; Myneni, Ranga B.

    2007-01-01

    We analyze the contribution of ecosystem services to GDP and use this contribution to calculate an empirical price for ecosystem services. Net primary production is used as a proxy for ecosystem services and, along with capital and labor, is used to estimate a Cobb Douglas production function from an international panel. A positive output elasticity for net primary production probably measures both marketed and nonmarketed contributions of ecosystems services. The production function is used to calculate the marginal product of net primary production, which is the shadow price for ecosystem services. The shadow price generally is greatest for developed nations, which have larger technical scalars and use less net primary production per unit output. The rate of technical substitution indicates that the quantity of capital needed to replace a unit of net primary production tends to increase with economic development, and this rate of replacement may ultimately constrain economic growth. (author)

  5. X-Ray Shadowing Experiments Toward Infrared Dark Clouds

    Science.gov (United States)

    Anderson, L. E.; Snowden, S.; Bania, T. M.

    2009-01-01

    We searched for X-ray shadowing toward two infrared dark clouds (IRDCs) using the MOS detectors on XMM-Newton to learn about the Galactic distribution of X-ray emitting plasma. IRDCs make ideal X-ray shadowing targets of 3/4 keY photons due to their high column densities, relatively large angular sizes, and known kinematic distances. Here we focus on two clouds near 30 deg Galactic longitude at distances of 2 and 5 kpc from the Sun. We derive the foreground and background column densities of molecular and atomic gas in the direction of the clouds. We find that the 3/4 ke V emission must be distributed throughout the Galactic disk. It is therefore linked to the structure of the cooler material of the ISM, and to the birth of stars.

  6. X-RAY SHADOWING EXPERIMENTS TOWARD INFRARED DARK CLOUDS

    International Nuclear Information System (INIS)

    Anderson, L. D.; Bania, T. M.; Snowden, S. L.

    2010-01-01

    We searched for X-ray shadowing toward two infrared dark clouds (IRDCs) using the MOS detectors on XMM-Newton to learn about the Galactic distribution of X-ray emitting plasma. IRDCs make ideal X-ray shadowing targets of 3/4 keV photons due to their high column densities, relatively large angular sizes, and known kinematic distances. Here we focus on two clouds near 30 0 Galactic longitude at distances of 2 and 5 kpc from the Sun. We derive the foreground and background column densities of molecular and atomic gas in the direction of the clouds. We find that the 3/4 keV emission must be distributed throughout the Galactic disk. It is therefore linked to the structure of the cooler material of the interstellar medium and to the birth of stars.

  7. Wake models developed during the Wind Shadow project

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, S.; Ott, S.; Pena, A.; Berg, J.; Nielsen, M.; Rathmann, O.; Joergensen, H.

    2011-11-15

    The Wind Shadow project has developed and validated improved models for determining the wakes losses, and thereby the array efficiency of very large, closely packed wind farms. The rationale behind the project has been that the existing software has been covering these types of wind farms poorly, both with respect to the densely packed turbines and the large fetches needed to describe the collective shadow effects of one farm to the next. Further the project has developed the necessary software for the use of the models. Guidelines with recommendations for the use of the models are included in the model deliverables. The project has been carried out as a collaborative project between Risoe DTU, DONG, Vattenfall, DNV and VESTAS, and it has been financed by energinet.dk grant no. 10086. (Author)

  8. The Permanently Shadowed Regions of Dwarf Planet Ceres

    Science.gov (United States)

    Schorghofer, Norbert; Mazarico, Erwan; Platz, Thomas; Preusker, Frank; Schroeder, Stefan E.; Raymond, Carol A.; Russell, Christopher T.

    2016-01-01

    Ceres has only a small spin axis tilt (4 deg), and craters near its rotational poles can experience permanent shadow and trap volatiles, as is the case on Mercury and on Earth's Moon. Topography derived from stereo imaging by the Dawn spacecraft is used to calculate direct solar irradiance that defines the extent of the permanently shadowed regions (PSRs). In the northern polar region, PSRs cover approximately 1800 sq km or 0.13% of the hemisphere, and most of the PSRs are cold enough to trap water ice over geological time periods. Based on modeling of the water exosphere, water molecules seasonally reside around the winter pole and ultimately an estimated 0.14% of molecules get trapped. Even for the lowest estimates of the amount of available water, this predicts accumulation rates in excess of loss rates, and hence, there should be fresh ice deposits in the cold traps.

  9. Shadow Areas Robust Matching Among Image Sequence in Planetary Landing

    Science.gov (United States)

    Ruoyan, Wei; Xiaogang, Ruan; Naigong, Yu; Xiaoqing, Zhu; Jia, Lin

    2017-01-01

    In this paper, an approach for robust matching shadow areas in autonomous visual navigation and planetary landing is proposed. The approach begins with detecting shadow areas, which are extracted by Maximally Stable Extremal Regions (MSER). Then, an affine normalization algorithm is applied to normalize the areas. Thirdly, a descriptor called Multiple Angles-SIFT (MA-SIFT) that coming from SIFT is proposed, the descriptor can extract more features of an area. Finally, for eliminating the influence of outliers, a method of improved RANSAC based on Skinner Operation Condition is proposed to extract inliers. At last, series of experiments are conducted to test the performance of the approach this paper proposed, the results show that the approach can maintain the matching accuracy at a high level even the differences among the images are obvious with no attitude measurements supplied.

  10. AUTOMATIC SHADOW DETECTION IN AERIAL AND TERRESTRIAL IMAGES

    Directory of Open Access Journals (Sweden)

    Vander Luis de Souza Freitas

    Full Text Available Abstract: Shadows exist in almost all aerial and outdoor images, and they can be useful for estimating Sun position estimation or measuring object size. On the other hand, they represent a problem in processes such as object detection/recognition, image matching, etc., because they may be confused with dark objects and change the image radiometric properties. We address this problem on aerial and outdoor color images in this work. We use a filter to find low intensities as a first step. For outdoor color images, we analyze spectrum ratio properties to refine the detection, and the results are assessed with a dataset containing ground truth. For the aerial case we validate the detections depending of the hue component of pixels. This stage takes into account that, in deep shadows, most pixels have blue or violet wavelengths because of an atmospheric scattering effect.

  11. Medium Access Control for Opportunistic Concurrent Transmissions under Shadowing Channels.

    Science.gov (United States)

    Son, In Keun; Mao, Shiwen; Hur, Seung Min

    2009-01-01

    We study the problem of how to alleviate the exposed terminal effect in multi-hop wireless networks in the presence of log-normal shadowing channels. Assuming node location information, we propose an extension of the IEEE 802.11 MAC protocol that sched-ules concurrent transmissions in the presence of log-normal shadowing, thus mitigating the exposed terminal problem and improving network throughput and delay performance. We observe considerable improvements in throughput and delay achieved over the IEEE 802.11 MAC under various network topologies and channel conditions in ns-2 simulations, which justify the importance of considering channel randomness in MAC protocol design for multi-hop wireless networks.

  12. Limiting Cash Circulation as a Means to Combat Shadow Economy

    Directory of Open Access Journals (Sweden)

    Galina S. Panova

    2014-01-01

    Full Text Available The article deals with actual problems of modern state and development prospects of cash circulation in Russia and abroad; the comparative analysis of monetization of the economy of Russia and foreign countries; quantitative parameters of aggregate money turnover, including the value of cash and non-cash spheres; the correlations of macroeconomic variables and indicators of cash circulation in Russia. Special attention is given by the authors to the limitations of cash payments and settlements in the fight against shadow economy. In particular, researched the level of shadow economy; the relationship between cash money circulation and shadow economy; the problems encountered by foreign states in imposing administrative limits on the amount of payments in cash; provides specific recommendations and outlines the required steps to introduce such restrictions in Russia. It is concluded that the limitation of the maximum size of payments in cash can lead to simultaneous reduce the underground economy because revenues derived from the hidden and informal economic activities can be translated in non-cash form. However, in the long run, when adopting legislative restrictions on the payment of funds by individuals on their own bank accounts or, for example, need to prove the lawful origin of money if you make them into a bank account to limit payments in cash will be the first step towards the goal of reducing shadow economy in Russia. In general, limiting the cash circulation - multi-factor task - that requires the solution of economic, political, social, administrative, psychological problems. The overall decrease in cash money (up to the optimum, economically justified level, it will lead to lower inflation rates, the level of corruption, will improve the investment climate and the liberalization of the credit market in our country.

  13. Corruption’s Reflection: Iraq’s Shadow Economy

    Science.gov (United States)

    2005-03-01

    prostitution, smuggling, bribery, political corruption , protection rackets; • Transfers—petty theft (e.g. pickpockets), larceny(burglary and armed robbery...importantly the impact that governance failures such as corruption have had on the development of a shadow economy have been extensively documented...after opening my shop a government inspector came, and I just had to pay him a bribe .[25] How widespread these types of government shakedowns were

  14. Shadow-mask evaporation through monolayer-modified nanostencils

    OpenAIRE

    Kolbel, M; Tjerkstra, RW; Brugger, J; van Rijn, CJM; Nijdam, W; Huskens, J; Reinhoudt, DN

    2002-01-01

    Gradual clogging of the apertures of nanostencils used as miniature shadow masks in metal evaporations can be reduced by coating the stencil with self-assembled monolayers (SAM). This is quantified by the dimensions (height and volume) of gold features obtained by nanostencil evaporation as measured by scanning electron microscopy (SEM) and atomic force microscopy (AFM). An increase in material deposition through the apertures by more than 100% can be achieved with SAM-coated stencils, which ...

  15. Diffractive production off nuclei-shadow of hadronic bremsstrahlung

    International Nuclear Information System (INIS)

    Bialas, A.; Czyz, W.

    1974-01-01

    Diffractive production on nuclei is calculated using as an input a specific model for diffractive production on nucleons. In this model diffractive production is described as a shadow of non-diffractive multiple production of particles. The mechanism for non-diffractive production is taken to be hadronic bremsstrahlung of independently produced clusters. It is shown that such a model naturally explains the strikingly simple pattern of absorption observed in coherent production on nuclei. Possible generalizations of these results are indicated. (author)

  16. Corruption, shadow economy and income inequality: evidence from Asia

    OpenAIRE

    Kar, Saibal; Saha, Shrabani

    2012-01-01

    A number of recent studies for Latin America show that as the size of the informal economy grows, corruption is less harmful to inequality. We investigate if this relationship is equally compelling for developing countries in Asia where corruption, inequality and shadow economies are considerably large. We use Panel Least Square and Fixed Effects Models for Asia to find that both 'Corruption Perception Index' and 'ICRG' index are sensitive to a number of important macroeconomic variables. We ...

  17. Shadow Banking – Developments in Times of Financial Crisis

    Directory of Open Access Journals (Sweden)

    Bogdan Munteanu

    2016-01-01

    The paper considers the following entities and activities, without limitation to or completenessof viewpoints: finance companies, asset backed financial instruments, structured investments,financing vehicles, money market funds, asset managers, credit hedge funds and venture capital,providing characteristics of shadow banking and their economic functions relative to the classicbanking system, as they pose a systemic risk due to asymmetric information and gaps created inmatching liquidity tenures with duration, by using synthetic leverage finance.

  18. A shadowing lemma for quasi-hyperbolic strings of flows

    Science.gov (United States)

    Han, Bo; Wen, Xiao

    2018-01-01

    In this paper we prove a shadowing lemma for pseudo orbits made by quasi-hyperbolic strings. We allow singularities in question and hence, in particular, the quasi-hyperbolic strings are formulated by the rescaled linear Poincaré flow instead of the usual linear Poincaré flow. We also introduce the sectional Poincaré map and rescaled sectional Poincaré map for Lipschitz vector fields on Banach spaces in the article.

  19. A 1K shadow RAM for circumvention applications

    International Nuclear Information System (INIS)

    Murray, J.R.

    1991-01-01

    This paper reports that circumvention applications require a memory that retains data through radiation (total dose and transient) and loss of power. Various memory technologies have been reviewed and none, as yet, can meet, these requirements. However, if complementary metal oxide silicon (CMOS) and silicon nitride oxide silicon (SNOS) memories are combined in a shadow RAM (random access memory) configuration, the requirements can be fulfilled

  20. Experimental observations of surface electrostatic wave on KT-5B tokamak

    International Nuclear Information System (INIS)

    Zhu Shiyao; Han Shensheng

    1991-01-01

    Shear Alfven waves have been successfully excited in KT-5B small tokamak by means of the one turn longitudinal loop antenna located in the shadow area. The measured antenna loadings show their rich structure, and the loadings are also found to be sensitive to the plasma current. Preliminary evidence of surface electrostatic wave was observed

  1. COMPUTER-AIDED DETECTION OF ACINAR SHADOWS IN CHEST RADIOGRAPHS

    Directory of Open Access Journals (Sweden)

    Tao Xu

    2013-05-01

    Full Text Available Despite the technological advances in medical diagnosis, accurate detection of infectious tuberculosis (TB still poses challenges due to complex image features and thus infectious TB continues to be a public health problem of global proportions. Currently, the detection of TB is mainly conducted visually by radiologists examining chest radiographs (CXRs. To reduce the backlog of CXR examination and provide more precise quantitative assessment, computer-aided detection (CAD systems for potential lung lesions have been increasingly adopted and commercialized for clinical practice. CADs work as supporting tools to alert radiologists on suspected features that could have easily been neglected. In this paper, an effective CAD system aimed for acinar shadow regions detection in CXRs is proposed. This system exploits textural and photometric features analysis techniques which include local binary pattern (LBP, grey level co-occurrence matrix (GLCM and histogram of oriented gradients (HOG to analyze target regions in CXRs. Classification of acinar shadows using Adaboost is then deployed to verify the performance of a combination of these techniques. Comparative study in different image databases shows that the proposed CAD system delivers consistent high accuracy in detecting acinar shadows.

  2. Interconnectedness between shadow and traditional banking systems in Europe

    Directory of Open Access Journals (Sweden)

    Popović Svetlana

    2017-01-01

    Full Text Available The financial crisis that emerged in the US quickly spread across Europe, causing a severe banking and sovereign debt crisis. That revealed the importance of short-term financing for traditional banks, which increased their exposure to the financial conditions on the interbank market. Financial innovations, especially the securitization process led to the growing importance of different institutions within the shadow banking system - which undergo a credit, liquidity and maturity transformation, without accessing the central bank liquidity or other forms of guarantees. The European banks had an active role in the US securitization process, but also securitized the products from the European market. The authors used the available data from the ECB statistics on shadow bank entities, broadly and narrowly defined, in order to analyze the various measures of interconnectedness between the shadow and traditional banking systems. The analysis showed that non-regulated financial institutions pose severe systemic risks, not just because of their size, but also due to the strong web of interconnectedness with the regulated banking sector.

  3. Shock wave propagation in soda lime glass using optical ...

    Indian Academy of Sciences (India)

    2016-06-16

    Jun 16, 2016 ... out at the Raja Ramanna Centre for Advanced Tech- nology, Indore, India, using the chirped pulse shadow- graphy technique as well as the snap-shot technique, to study the evolution of shock waves in transparent soda lime glass targets and to observe the temporal variation of the shock velocity. A high ...

  4. Bootstrapping de-shadowing and self-calibration for scanning electron microscope photometric stereo

    International Nuclear Information System (INIS)

    Miyamoto, Atsushi; Chen, Deshan; Kaneko, Shun’ichi

    2014-01-01

    In this paper, we present a novel approach that addresses the blind reconstruction problem in scanning electron microscope (SEM) photometric stereo. Using only two observed images that suffer from shadowing effects, our method automatically calibrates the parameter and resolves shadowing errors for estimating an accurate three-dimensional (3D) shape and underlying shadowless images. We introduce a novel shadowing compensation model using image intensities for both cases of presence and absence of shadowing. With this model, the proposed de-shadowing algorithm iteratively compensates for image intensities and modifies the corresponding 3D surface. Besides de-shadowing, we introduce a practically useful self-calibration criterion by enforcing a good reconstruction. We show that incorrect parameters will engender significant distortions of 3D reconstructions in shadowed regions during the de-shadowing procedure. This motivated us to design the self-calibration criterion by utilizing shadowing to pursue the proper parameter that produces the best reconstruction with least distortions. As a result, we develop a bootstrapping approach for simultaneous de-shadowing and self-calibration in SEM photometric stereo. Extensive experiments on real image data demonstrate the effectiveness of our method. (paper)

  5. SOCIO-ECONOMIC NATURE OF SHADOW ECONOMY AND CAUSES OF ITS DEVELOPMENT IN ENTREPRENEURSHIP

    Directory of Open Access Journals (Sweden)

    I. Mazur

    2017-01-01

    Full Text Available The socio-economic nature of the shadow economy is revealed. The shadow economy has both positive and negative signs for the society; the possibility for the population to survive in conditions of economic crisis, reducing transaction costs authors refer to positive signs, and the destructive economic development to negative. The common (prohibitions and restrictions and partial (high tax burden and inefficient system of its administration; numerous bureaucratic procedures; mistrust to the government institutions and the judiciary; corruption in all levels of the governance, etc. causes of the shadow economy in entrepreneurship are disclosed. It is argued that the shadow economy is neither a sector nor a certain part of the legal economy, it can be in any sector of the legal economy closely interlaced with it, and therefore its limits cannot be clearly identified (determine in the formal economy. The shadow economy is not possible to determine especially in the information society. The categories of the shadow economy and its structuring are suggested. It has been researched the historical roots of the shadow economy spread in entrepreneurship, and lie in the shadow of public-private partnership which carries interests of "civil servant-entrepreneurs" and allows to manage state resources and control market. Therefore, the shadow policy creates favorable conditions for the entrepreneurs to work in the shadow. At the same time, access to the shadow entails stricter regulation by the state. It is proved that corruption is a part of the shadow economy, not an independent phenomenon, so they should be research comprehensively and systematically. Instead of overcoming the shadow economy and its component - corruption has been suggested to establish favorable business environment for their unfavorable existence, that is to carry out deshadowing of the economy.

  6. The shadow of a doubt ? Evidence for perceptuo-motor linkage during auditory and audiovisual close shadowing

    Directory of Open Access Journals (Sweden)

    Lucie eScarbel

    2014-06-01

    Full Text Available One classical argument in favor of a functional role of the motor system in speech perception comes from the close shadowing task in which a subject has to identify and to repeat as quickly as possible an auditory speech stimulus. The fact that close shadowing can occur very rapidly and much faster than manual identification of the speech target is taken to suggest that perceptually-induced speech representations are already shaped in a motor-compatible format. Another argument is provided by audiovisual interactions often interpreted as referring to a multisensory-motor framework. In this study, we attempted to combine these two paradigms by testing whether the visual modality could speed motor response in a close-shadowing task. To this aim, both oral and manual responses were evaluated during the perception of auditory and audio-visual speech stimuli, clear or embedded in white noise. Overall, oral responses were faster than manual ones, but it also appeared that they were less accurate in noise, which suggests that motor representations evoked by the speech input could be rough at a first processing stage. In the presence of acoustic noise, the audiovisual modality led to both faster and more accurate responses than the auditory modality. No interaction was however observed between modality and response. Altogether, these results are interpreted within a two-stage sensory-motor framework, in which the auditory and visual streams are integrated together and with internally generated motor representations before a final decision may be available.

  7. An image-space parallel convolution filtering algorithm based on shadow map

    Science.gov (United States)

    Li, Hua; Yang, Huamin; Zhao, Jianping

    2017-07-01

    Shadow mapping is commonly used in real-time rendering. In this paper, we presented an accurate and efficient method of soft shadows generation from planar area lights. First this method generated a depth map from light's view, and analyzed the depth-discontinuities areas as well as shadow boundaries. Then these areas were described as binary values in the texture map called binary light-visibility map, and a parallel convolution filtering algorithm based on GPU was enforced to smooth out the boundaries with a box filter. Experiments show that our algorithm is an effective shadow map based method that produces perceptually accurate soft shadows in real time with more details of shadow boundaries compared with the previous works.

  8. ANALYZING SPECTRAL CHARACTERISTICS OF SHADOW AREA FROM ADS-40 HIGH RADIOMETRIC RESOLUTION AERIAL IMAGES

    Directory of Open Access Journals (Sweden)

    Y.-T. Hsieh

    2016-06-01

    Full Text Available The shadows in optical remote sensing images are regarded as image nuisances in numerous applications. The classification and interpretation of shadow area in a remote sensing image are a challenge, because of the reduction or total loss of spectral information in those areas. In recent years, airborne multispectral aerial image devices have been developed 12-bit or higher radiometric resolution data, including Leica ADS-40, Intergraph DMC. The increased radiometric resolution of digital imagery provides more radiometric details of potential use in classification or interpretation of land cover of shadow areas. Therefore, the objectives of this study are to analyze the spectral properties of the land cover in the shadow areas by ADS-40 high radiometric resolution aerial images, and to investigate the spectral and vegetation index differences between the various shadow and non-shadow land covers. According to research findings of spectral analysis of ADS-40 image: (i The DN values in shadow area are much lower than in nonshadow area; (ii DN values received from shadowed areas that will also be affected by different land cover, and it shows the possibility of land cover property retrieval as in nonshadow area; (iii The DN values received from shadowed regions decrease in the visible band from short to long wavelengths due to scattering; (iv The shadow area NIR of vegetation category also shows a strong reflection; (v Generally, vegetation indexes (NDVI still have utility to classify the vegetation and non-vegetation in shadow area. The spectral data of high radiometric resolution images (ADS-40 is potential for the extract land cover information of shadow areas.

  9. The impact of economic globalization on the shadow economy in Egypt

    OpenAIRE

    Farzanegan, Mohammad Reza; Hassan, Mai

    2017-01-01

    This study examines the economic globalization and the shadow economy nexus in Egypt. Using time series data from 1976 to 2013, the impulse response analysis shows that the response of the shadow economy in Egypt to positive shocks in economic globalization is negative and statistically significant for the first three years following the shock. This finding is obtained by controlling for several intermediary channels in globalization-shadow economy nexus such as education, government spending...

  10. Experimental test of the shadowing effect in Smith-Purcell radiation

    International Nuclear Information System (INIS)

    Naumenko, G.A.; Potylitsyn, A.P.; Popov, Yu.A.; Shevelev, M.V

    2011-01-01

    The observation of a shadowing effect of a relativistic electron Coulomb field for the Smith-Purcell radiation generation is presented in this paper. For this purpose the surface current from the closest surface of grating element to the electron beam was measured for a downstream one shadowed by upstream element. The experimental results showed that shadowing effect for Smith-Purcell radiation depends on grating geometry.

  11. Wave dissipation due to spatially varying bottom roughness: Observations from Oahu, Hawaii

    Science.gov (United States)

    Siegelman, M. N.; Merrifield, M. A.; Becker, J. M.; Pawlak, G. R.; Reyns, J.

    2016-02-01

    The influence of bottom friction on waves shoaling over reef topography prior to breaking is examined using across-shore array of wave sensors on the Leeward side of Oahu during the winter of 2014. Offshore wave heights ranged from 2 to 5 m during a succession of northwest swell events. Wave energy flux is approximately conserved between an offshore wave buoy and the deepest wave sensor at 15 m depth. Between 15 m and 6 m depths, where rough reef bathymetry replaces sand, significant dissipation is inferred with a 60% reduction in the wave energy flux. Equating the energy flux divergence to bottom friction dissipation results in a wave friction factor of 0.38 ± 0.03, higher than typical wave factors reported in previous reef field studies. The estimated friction factor between 6 m and 5 m reduces to 0.14 ± 0.01. AUV surveys of the study site provide high resolution depth measurements that are used to relate bottom roughness to the variable friction factor estimated across the transect. A numerical model is used to assess the influence of the high friction factors on simulations over two-dimensional bathymetry. The results highlight the need for spatially dependent bottom roughness estimates for accurate wave predictions in reef environments.

  12. Single-Image Shadow Removal Using 3D Intensity Surface Modeling.

    Science.gov (United States)

    He, Kai; Zhen, Rui; Yan, Jiaxing; Ge, Yunfeng

    2017-09-11

    Shadow removal from a single image is a challenging problem, whose solution is proposed in this study using 3D intensity surface modeling. Due to the high-order textural content in the original images, a direct modeling of the intensity surface of shadow image is difficult. In this study, image decomposition technology is used as an edge-preserving filter to remove the textural detail while keeping the local-smoothness pattern of image intensity surface. Using 3D modeling, a proper intensity surface of illumination in shadow region can be obtained based on that corresponding to the same texture in the non-shadow one. Thus, the intensity surface of shadow region can be compensated with a respective shadow-removal. Experimental results demonstrate the effectiveness of the proposed approach in the aspect of single-image shadow removal. In contrast to the alternative methods, it is not limited by additional assumptions or conditions; moreover, it can deal with the non-uniform and curved surface shadows, and is applicable to the shadow regions consisting of different types of textures.

  13. How to use 3D shadows for simple microscopy and vibrometry

    Science.gov (United States)

    Parikesit, Gea O. F.; Kusumaningtyas, Indraswari

    2017-07-01

    In 2014, we reported that shadows can be displayed in 3D using a stereoscopic setup. We now report that the 3D shadows can also be used to perform simple measurements, which are suitable for physics education in schools and colleges. Two different types of measurements are demonstrated, i.e. microscopy and vibrometry. Both types of measurements take advantage of the geometrical optics of the 3D shadows, where the 3D position of an object can be estimated using the coordinates of the colored light sources and the coordinates of the colored shadow images. We also include several student activities that can raise the students’ curiosity and capability.

  14. A hardware architecture for real-time shadow removal in high-contrast video

    Science.gov (United States)

    Verdugo, Pablo; Pezoa, Jorge E.; Figueroa, Miguel

    2017-09-01

    Broadcasting an outdoor sports event at daytime is a challenging task due to the high contrast that exists between areas in the shadow and light conditions within the same scene. Commercial cameras typically do not handle the high dynamic range of such scenes in a proper manner, resulting in broadcast streams with very little shadow detail. We propose a hardware architecture for real-time shadow removal in high-resolution video, which reduces the shadow effect and simultaneously improves shadow details. The algorithm operates only on the shadow portions of each video frame, thus improving the results and producing more realistic images than algorithms that operate on the entire frame, such as simplified Retinex and histogram shifting. The architecture receives an input in the RGB color space, transforms it into the YIQ space, and uses color information from both spaces to produce a mask of the shadow areas present in the image. The mask is then filtered using a connected components algorithm to eliminate false positives and negatives. The hardware uses pixel information at the edges of the mask to estimate the illumination ratio between light and shadow in the image, which is then used to correct the shadow area. Our prototype implementation simultaneously processes up to 7 video streams of 1920×1080 pixels at 60 frames per second on a Xilinx Kintex-7 XC7K325T FPGA.

  15. Planetary-like spirals caused by moving shadows in transition discs

    Science.gov (United States)

    Montesinos, Matías; Cuello, Nicolás

    2018-03-01

    Shadows and spirals seem to be common features of transition discs. Among the spiral-triggering mechanisms proposed, only one establishes a causal link between shadows and spirals so far. In fact, provided the presence of shadows in the disc, the combined effect of temperature gradient and differential disc rotation creates strong azimuthal pressure gradients. After several thousand years, grand-design spirals develop in the gas phase. Previous works have only considered static shadows caused by an inclined inner disc. However, in some cases, the inner regions of circumbinary discs can break and precess. Thus, it is more realistic to consider moving shadow patterns in the disc. In this configuration, the intersection between the inner and the outer discs defines the line of nodes at which the shadows are cast. Here, we consider moving shadows and study the resulting circumbinary disc structure. We find that only static and prograde shadows trigger spirals, in contrast to retrograde ones. Interestingly, if a region of the disc corotates with the shadow, a planet-like signature develops at the co-rotation position. The resulting spirals resemble those caused by a planet embedded in the disc, with similar pitch angles.

  16. Robust Lane Sensing and Departure Warning under Shadows and Occlusions

    Directory of Open Access Journals (Sweden)

    Miguel Torres-Torriti

    2013-03-01

    Full Text Available A prerequisite for any system that enhances drivers’ awareness of road conditions and threatening situations is the correct sensing of the road geometry and the vehicle’s relative pose with respect to the lane despite shadows and occlusions. In this paper we propose an approach for lane segmentation and tracking that is robust to varying shadows and occlusions. The approach involves color-based clustering, the use of MSAC for outlier removal and curvature estimation, and also the tracking of lane boundaries. Lane boundaries are modeled as planar curves residing in 3D-space using an inverse perspective mapping, instead of the traditional tracking of lanes in the image space, i.e., the segmented lane boundary points are 3D points in a coordinate frame fixed to the vehicle that have a depth component and belong to a plane tangent to the vehicle’s wheels, rather than 2D points in the image space without depth information. The measurement noise and disturbances due to vehicle vibrations are reduced using an extended Kalman filter that involves a 6-DOF motion model for the vehicle, as well as measurements about the road’s banking and slope angles. Additional contributions of the paper include: (i the comparison of textural features obtained from a bank of Gabor filters and from a GMRF model; and (ii the experimental validation of the quadratic and cubic approximations to the clothoid model for the lane boundaries. The results show that the proposed approach performs better than the traditional gradient-based approach under different levels of difficulty caused by shadows and occlusions.

  17. Asymptotic Ergodic Capacity Analysis of Composite Lognormal Shadowed Channels

    KAUST Repository

    Ansari, Imran Shafique

    2015-05-01

    Capacity analysis of composite lognormal (LN) shadowed links, such as Rician-LN, Gamma-LN, and Weibull-LN, is addressed in this work. More specifically, an exact closed-form expression for the moments of the end-to-end signal-to-noise ratio (SNR) of a single composite link transmission system is presented in terms of well- known elementary functions. Capitalizing on these new moments expressions, we present asymptotically tight lower bounds for the ergodic capacity at high SNR. All the presented results are verified via computer-based Monte-Carlo simulations. © 2015 IEEE.

  18. Polarization-encoded optical shadow-casting logic units: design.

    Science.gov (United States)

    Karim, M A; Awwal, A A; Cherri, A K

    1987-07-15

    A general design algorithm is presented for the multioutput polarization-encoded optical shadow-casting scheme. A set of POSC equations is obtained from the truth table of the desired logic unit and is solved in terms of four possible pixel characteristics (transparent, opaque, vertically polarized, and horizontally polarized) and four possible source characteristics (off, unpolarized, vertically polarized, and horizontally polarized). To demonstrate its feasibility, the algorithm is used to determine the input pixel characteristics of a full adder and a full subtracter.

  19. Shadows and strong gravitational lensing: a brief review

    Science.gov (United States)

    Cunha, Pedro V. P.; Herdeiro, Carlos A. R.

    2018-04-01

    For ultra compact objects, light rings and fundamental photon orbits (FPOs) play a pivotal role in the theoretical analysis of strong gravitational lensing effects, and of BH shadows in particular. In this short review, specific models are considered to illustrate how FPOs can be useful in order to understand some non-trivial gravitational lensing effects. This paper aims at briefly overviewing the theoretical foundations of these effects, touching also some of the related phenomenology, both in general relativity and alternative theories of gravity, hopefully providing some intuition and new insights for the underlying physics, which might be critical when testing the Kerr black hole hypothesis.

  20. CONSTRUCTING A COURSE ON INDONESIAN SHADOW PUPPETS FOR INTERNATIONAL STUDENTS

    Directory of Open Access Journals (Sweden)

    Yosep Bambang Margono Slamet

    2014-12-01

    Full Text Available Abstract: This paper is a course design on Indonesian shadow puppet to promote Indonesian culture to international students as a way of building a cultural bridge to create global citizens. In todays world, it is of paramount importance for every individual from diverse cultural, linguistic, and ethnic backgrounds to understand each other and work together. Creating this course is to introduce and promote an aspect Indonesian culture so that international students are more interested in and knowledgeable of Indonesian people and culture in general. Even though students only learn an aspect of Indonesian culture it is expected that they will be able to explore Indonesian culture in a broad sense.

  1. When a giant falls, dwarfs have no shadow

    OpenAIRE

    Juan Gérvas; Mercedes Pérez Fernández

    2011-01-01

    It is said that in times of war old people bury young men. As we live in times of peace, and we are old, youngsters will need to bury us. It is said that we become good people after we die. But some of us were good before dying. They were good, generous and honored, wise and tender, effectively human. Some who passed away used to give us a cozy and protective shadow, and their absence leaves us unsheltered, alone with danger. A long time ago, one of our children asked to us: “When an old wise...

  2. Congestion management in a smart grid via shadow prices

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Andersen, Palle; Stoustrup, Jakob

    2012-01-01

    We consider a distribution grid interconnecting a number of consumers with flexible power consumption. Each consumer is under the jurisdiction of exactly one balancing responsible party (BRP), who buys energy at a day-ahead electricity market on behalf of the consumer. We illustrate how BRPs can...... utilize the flexibility of the consumers to minimize the imbalance between the consumed and the purchased energy thereby avoiding trading balancing energy at unfavorable prices. Further we show how shadow prices on the distribution lines can be used to resolve grid congestion without information sharing...

  3. Shadow Affect in Urban Digital (Post Screen) Art

    DEFF Research Database (Denmark)

    Toft, Tanya Søndergaard

    2014-01-01

    The paper considers an affective turn in artistic practices with interactive urban digital screen-based art that evokes a behavioral response in the audience, which I propose as a symptom of the post screen. I propose the affective experience as a mode of exploring presence in the artwork through...... “shadow affect”, as an alternative to experiencing self identification and representation. I argue that a phenomenological understanding is necessary in place of a techno-aesthetic perspective, which would allow for more nuanced understandings of human experience in our digital reality....

  4. Leaking privacy and shadow profiles in online social networks.

    Science.gov (United States)

    Garcia, David

    2017-08-01

    Social interaction and data integration in the digital society can affect the control that individuals have on their privacy. Social networking sites can access data from other services, including user contact lists where nonusers are listed too. Although most research on online privacy has focused on inference of personal information of users, this data integration poses the question of whether it is possible to predict personal information of nonusers. This article tests the shadow profile hypothesis, which postulates that the data given by the users of an online service predict personal information of nonusers. Using data from a disappeared social networking site, we perform a historical audit to evaluate whether personal data of nonusers could have been predicted with the personal data and contact lists shared by the users of the site. We analyze personal information of sexual orientation and relationship status, which follow regular mixing patterns in the social network. Going back in time over the growth of the network, we measure predictor performance as a function of network size and tendency of users to disclose their contact lists. This article presents robust evidence supporting the shadow profile hypothesis and reveals a multiplicative effect of network size and disclosure tendencies that accelerates the performance of predictors. These results call for new privacy paradigms that take into account the fact that individual privacy decisions do not happen in isolation and are mediated by the decisions of others.

  5. Tomographic Particle Image Velocimetry using Smartphones and Colored Shadows

    KAUST Repository

    Aguirre-Pablo, Andres A.

    2017-06-12

    We demonstrate the viability of using four low-cost smartphone cameras to perform Tomographic PIV. We use colored shadows to imprint two or three different time-steps on the same image. The back-lighting is accomplished with three sets of differently-colored pulsed LEDs. Each set of Red, Green & Blue LEDs is shone on a diffuser screen facing each of the cameras. We thereby record the RGB-colored shadows of opaque suspended particles, rather than the conventionally used scattered light. We subsequently separate the RGB color channels, to represent the separate times, with preprocessing to minimize noise and cross-talk. We use commercially available Tomo-PIV software for the calibration, 3-D particle reconstruction and particle-field correlations, to obtain all three velocity components in a volume. Acceleration estimations can be done thanks to the triple pulse illumination. Our test flow is a vortex ring produced by forcing flow through a circular orifice, using a flexible membrane, which is driven by a pressurized air pulse. Our system is compared to a commercial stereoscopic PIV system for error estimations. We believe this proof of concept experiment will make this technique available for education, industry and scientists for a fraction of the hardware cost needed for traditional Tomo-PIV.

  6. Racing the Moon’s shadow with Concorde 001

    CERN Document Server

    Léna, Pierre

    2015-01-01

    This is the unique story of  observing a total solar exlipse for no less than 74 consecutive minutes. On the summer morning of June 30, 1973, the Sun rises on the Canary Islands. But it is strangely indented by the Moon. The eclipse of the century has just begun. From the west, the lunar shadow rushes to the African coast at a velocity of over 2000 kilometers per hour. Astronomers on the ground will enjoy seven short minutes of total eclipse to study the solar corona - too short for Pierre Lena and seven scientists who board the Concorde 001 prototype, an extraordinary plane to become the first commercial supersonic aircraft. With André Turcat as chief pilot and a crew of five, at 17000 m altitude, the aircraft remains in the lunar shadow for 74 minutes, a record time of scientific observations not yet beaten and allowing for exceptional measurements. Science, technology, aviation and history combine in the story of a unique human adventure aboard a legendary aircraft, illustrated with a rich and original ...

  7. Tomographic Particle Image Velocimetry using Smartphones and Colored Shadows.

    Science.gov (United States)

    Aguirre-Pablo, Andres A; Alarfaj, Meshal K; Li, Er Qiang; Hernández-Sánchez, J F; Thoroddsen, Sigurdur T

    2017-06-16

    We demonstrate the viability of using four low-cost smartphone cameras to perform Tomographic PIV. We use colored shadows to imprint two or three different time-steps on the same image. The back-lighting is accomplished with three sets of differently-colored pulsed LEDs. Each set of Red, Green & Blue LEDs is shone on a diffuser screen facing each of the cameras. We thereby record the RGB-colored shadows of opaque suspended particles, rather than the conventionally used scattered light. We subsequently separate the RGB color channels, to represent the separate times, with preprocessing to minimize noise and cross-talk. We use commercially available Tomo-PIV software for the calibration, 3-D particle reconstruction and particle-field correlations, to obtain all three velocity components in a volume. Acceleration estimations can be done thanks to the triple pulse illumination. Our test flow is a vortex ring produced by forcing flow through a circular orifice, using a flexible membrane, which is driven by a pressurized air pulse. Our system is compared to a commercial stereoscopic PIV system for error estimations. We believe this proof of concept experiment will make this technique available for education, industry and scientists for a fraction of the hardware cost needed for traditional Tomo-PIV.

  8. Testing the Concept of Drift Shadow at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    J.B. Paces; L.A. Neymark; T. Ghezzehei; P.F. Dobson

    2006-01-01

    If proven, the concept of drift shadow, a zone of reduced water content and slower ground-water travel time beneath openings in fractured rock of the unsaturated zone, may increase performance of a proposed geologic repository for high-level radioactive waste at Yucca Mountain. To test this concept under natural-flow conditions present in the proposed repository horizon, isotopes within the uranium-series decay chain (uranium-238, uranium-234, and thorium-230, or 238 U- 234 U- 230 Th) have been analyzed in samples of rock from beneath four naturally occurring lithophysal cavities. All samples show 234 U depletion relative to parent 238 U, indicating varying degrees of water-rock interaction over the past million years. Variations in 234 U/ 238 U activity ratios indicate that depletion of 234 U relative to 238 U can be either smaller or greater in rock beneath cavity floors relative to rock near cavity margins. These results are consistent with the concept of drift shadow and with numerical simulations of meter-scale spherical cavities in fractured tuff. Differences in distribution patterns of 234 U/ 238 U activity ratios in rock beneath the cavity floors are interpreted to reflect differences in the amount of past seepage into lithophysal cavities, as indicated by the abundance of secondary mineral deposits present on the cavity floors

  9. Shadow banking, relationship banking, and the economics of depression

    Directory of Open Access Journals (Sweden)

    Antonio Bianco

    2015-12-01

    Full Text Available The paper explores whether a theory of banks doing ‘finance through money creation’ implies a reconsideration of demand-side macro theory as well. To this aim, a simple methodological accounting model of the influence of financial markets over the real economy is presented. The model allows a tidy comparison of relationship and shadow banking, interpreted as alternative schemes of liquidity (not credit risk management. The model emphasizes the interdependencies in entrepreneurs’ animal spirits, liquidity risk management schemes adopted by financial institutions, and effective demand of households. The underlying idea is that fluctuations in the composition of property incomes trigger fluctuations in non-financial investment that, in turn, drive fluctuations in spending. The article finds that both relationship and shadow banking must have a pro-cyclical impact, and differences are essentially based on different liquidity risk management aggregate cost functions. The model developed here suggests that securitisation does not per se affect the financial sustainability of the growth process, but regulatory measures aimed at checking predatory lending and re-securitisation activities are needed to avoid possible adverse impacts on animal spirits. JEL codes: E44, G20, O16.

  10. Tomographic Particle Image Velocimetry Using Colored Shadow Imaging

    KAUST Repository

    Alarfaj, Meshal K.

    2016-02-01

    Tomographic Particle Image Velocimetry Using Colored Shadow Imaging by Meshal K Alarfaj, Master of Science King Abdullah University of Science & Technology, 2015 Tomographic Particle image velocimetry (PIV) is a recent PIV method capable of reconstructing the full 3D velocity field of complex flows, within a 3-D volume. For nearly the last decade, it has become the most powerful tool for study of turbulent velocity fields and promises great advancements in the study of fluid mechanics. Among the early published studies, a good number of researches have suggested enhancements and optimizations of different aspects of this technique to improve the effectiveness. One major aspect, which is the core of the present work, is related to reducing the cost of the Tomographic PIV setup. In this thesis, we attempt to reduce this cost by using an experimental setup exploiting 4 commercial digital still cameras in combination with low-cost Light emitting diodes (LEDs). We use two different colors to distinguish the two light pulses. By using colored shadows with red and green LEDs, we can identify the particle locations within the measurement volume, at the two different times, thereby allowing calculation of the velocities. The present work tests this technique on the flows patterns of a jet ejected from a tube in a water tank. Results from the images processing are presented and challenges discussed.

  11. Improving Shadow Suppression for Illumination Robust Face Recognition

    KAUST Repository

    Zhang, Wuming

    2017-10-13

    2D face analysis techniques, such as face landmarking, face recognition and face verification, are reasonably dependent on illumination conditions which are usually uncontrolled and unpredictable in the real world. An illumination robust preprocessing method thus remains a significant challenge in reliable face analysis. In this paper we propose a novel approach for improving lighting normalization through building the underlying reflectance model which characterizes interactions between skin surface, lighting source and camera sensor, and elaborates the formation of face color appearance. Specifically, the proposed illumination processing pipeline enables the generation of Chromaticity Intrinsic Image (CII) in a log chromaticity space which is robust to illumination variations. Moreover, as an advantage over most prevailing methods, a photo-realistic color face image is subsequently reconstructed which eliminates a wide variety of shadows whilst retaining the color information and identity details. Experimental results under different scenarios and using various face databases show the effectiveness of the proposed approach to deal with lighting variations, including both soft and hard shadows, in face recognition.

  12. Study on the Performance of the “Pendulor” Wave Energy Converter in an Array Configuration

    Directory of Open Access Journals (Sweden)

    Sudath Prasanna Gunawardane

    2016-04-01

    Full Text Available For over three decades the “Pendulor” wave energy device has had a significant influence in this field, triggering several research endeavours. It includes a top-hinged flap propelled by the standing waves produced in a caisson with a back wall on the leeward side. However, one of the main disadvantages which impedes its progress is the enormous expense involved in the construction of the custom made typical caisson structure, about a little more than one-quarter of the wave length. In this study, the influence of such design parameters on the performance of the device is investigated, via numerical modelling for a device arranged in an array configuration, for irregular waves. The potential wave theory is applied to derive the frequency-dependent hydrodynamic parameters by making a distinction in the fluid domain into a separate sea side and lee side. The Cummins equation was utilised for the development of the time domain equation of motion while the transfer function estimation methods were used to solve the convolution integrals. Finally, the device was tested numerically for irregular wave conditions for a 50 kW class unit. It was observed that in irregular wave operating conditions, the caisson chamber length could be reduced by 40% of the value estimated for the regular waves. Besides, the device demonstrated around 80% capture efficiency for irregular waves thus allowing provision for avoiding the employment of any active control.

  13. The effect of shadow lines on a low concentrating photovoltaic system

    NARCIS (Netherlands)

    Janssen, H.J.J.; Sonneveld, P.J.; Swinkels, G.L.A.M.; Tuijl, van B.A.J.; Zwart, de H.F.

    2011-01-01

    In order to reduce the energy losses caused by shadow lines, three options are investigated. These are: 1. the use of two types of diodes; 2. the use of an ”ideal” diode based an active bypass by using MOS-FET’s [4] and 3. parallel switching of a number of cells between two shadow lines. The first

  14. The Job Shadow Assignment: Career Perceptions in Hospitality, Recreation and Tourism

    Science.gov (United States)

    Padron, Thomas C.; Fortune, Mary F.; Spielman, Melany; Tjoei, Sylvie

    2017-01-01

    The job shadow study measured student career perceptions related to hospitality, recreation and tourism (HRT) and instructional mode (face-to-face (F2F), hybrid, and online). College students self-selecting into three different course modalities taught by the same instructor job shadowed HRT professionals by using Internet and F2F interviews. The…

  15. Shadow Education in Spain: Examining Social Inequalities through the Analysis of PISA Results

    Science.gov (United States)

    Runte-Geidel, Ariadne; Marzo, Pedro Femia

    2015-01-01

    This article examines the use of shadow education by students of compulsory secondary education in Spain over the period 2000-2010. The study identifies the proportion of the student population that uses this type of education and examines how the use of shadow education has evolved during this period. Data was drawn from the student questionnaire…

  16. Discursive Shadowing in Linguistic Ethnography. Situated Practices and Circulating Discourses in Multilingual Schools

    Science.gov (United States)

    Dewilde, Joke; Creese, Angela

    2016-01-01

    We consider discursive shadowing as methodology in linguistic ethnography and how it refines our analyses of participants' situated practices. In addition to the constant and extended company the researcher and key participant keep with one another in the field, shadowing in a linguistic ethnographic approach includes the ubiquitous…

  17. Observation of the shadowing and antishadowing effects in pion-nucleus interactions

    International Nuclear Information System (INIS)

    Ion, D.B.; Nichitiu, F.

    1977-12-01

    The shadowing and antishadowing effects in the pion-nucleus interaction are investigated by using the available experimental data and the recent interpolations of the π + - p total cross sections. Pronounced shadowing is found in the energy regions of pion-nucleon resonances while the antishadowing effects are systematically observed at energies between two resonances. (author)

  18. Labor Market Institutions and Their Impact on Shadow Economies in Europe

    Czech Academy of Sciences Publication Activity Database

    Fialová, Kamila; Schneider, O.

    2014-01-01

    Roč. 5, č. 1 (2014), s. 1-40 ISSN 2038-1379 R&D Projects: GA ČR(CZ) GA14-15008S Institutional support: RVO:68378025 Keywords : labour market institutions * shadow economy * shadow employment Subject RIV: AH - Economics http://www.rei.unipg.it/rei/article/view/146/137

  19. A Study on Building an Efficient Job Shadowing Management Methodology for the Undergraduate Students

    Science.gov (United States)

    Sakoda, Koichi; Takahashi, Masakazu

    2014-01-01

    This paper describes heuristic knowledge through the job-shadowing project at the International University of Kagoshima, Japan. Job shadowing is one of the conventional in-house trainings given to the executive trainee cadets in North America and proved the effect of training in Leonard's paper for the conventional target such as the executive…

  20. Mapping the ultrasonic defect shadow in a pitch-catch mode

    International Nuclear Information System (INIS)

    Licht, H.; Hallet, J.B.

    1981-06-01

    In ultrasonic testing of metallic structures, the sound reflected from a discontinuity is usually used to determine its location and size. Here is described a technique for locating and sizing a discontinuity by mapping the shadow(s) it casts. A brief description of the technique is given. Results obtained from artificial notches and fatigue cracks are outlined and discussed

  1. Implementing content constraints in alpha-stratified adaptive testing using a shadow test approach

    NARCIS (Netherlands)

    van der Linden, Willem J.; Chang, Hua-Hua

    2001-01-01

    The methods of alpha-stratified adaptive testing and constrained adaptive testing with shadow tests are combined in this study. The advantages are twofold. First, application of the shadow test allows the researcher to implement any type of constraint on item selection in alpha-stratified adaptive

  2. Shadowing corrections to the derivative of the reduced cross-section ...

    Indian Academy of Sciences (India)

    where the shadowing corrections to the derivative of the parton structure functions are given by eqs (6) and (7). After substitution and rearranging [22] we find that the shad- owing correction to the longitudinal structure function is proportional to the shadowing corrections to the gluon distribution function as. Fsh. L (x, Q2) = ...

  3. Qualitative Shadowing as a Research Methodology for Exploring Early Childhood Leadership in Practice

    Science.gov (United States)

    Bøe, Marit; Hognestad, Karin; Waniganayake, Manjula

    2017-01-01

    This article explores qualitative shadowing as an interpretivist methodology, and explains how two researchers participating simultaneously in data collection using a video recorder, contextual interviews and video-stimulated recall interviews, conducted a qualitative shadowing study at six early childhood centres in Norway. This paper emerged…

  4. Art Therapy and Its Shadow: A Jungian Perspective on Professional Identity and Community.

    Science.gov (United States)

    Bouchard, Rene R.

    1998-01-01

    Through the lens of Jungian theory of the shadow, this article identifies ways in which its dynamics and manifestations occur in the field of art therapy. Introduces experiential exercises for discovering and working with the shadow and concludes with recommendations for transforming negative dynamics into creative solutions. (Author/MKA)

  5. effect of shadowing and multipath fading on the area spectral for cell

    African Journals Online (AJOL)

    user

    base station. This is because of excess attenuation of the signal due to fading and shadowing. Multipath fading and shadowing are major causes of performance degradation in mobile communication systems. This phenomenon which arises as a result of propagation effects (like scattering, diffraction and reflection), renders ...

  6. STUDY ON SHADOW EFFECTS OF VARIOUS FEATURES ON CLOSE RANGE THERMAL IMAGES

    Directory of Open Access Journals (Sweden)

    C. L. Liao

    2012-07-01

    Full Text Available Thermal infrared data become more popular in remote sensing investigation, for it could be acquired both in day and night. The change of temperature has special characteristic in natural environment, so the thermal infrared images could be used in monitoring volcanic landform, the urban development, and disaster prevention. Heat shadow is formed by reflecting radiating capacity which followed the objects. Because of poor spatial resolution of thermal infrared images in satellite sensor, shadow effects were usually ignored. This research focus on discussing the shadow effects of various features, which include metals and nonmetallic materials. An area-based thermal sensor, FLIR-T360 was selected to acquire thermal images. Various features with different emissivity were chosen as reflective surface to obtain thermal shadow in normal atmospheric temperature. Experiments found that the shadow effects depend on the distance between sensors and features, depression angle, object temperature and emissivity of reflective surface. The causes of shadow effects have been altered in the experiment for analyzing the variance in thermal infrared images. The result shows that there were quite different impacts by shadow effects between metals and nonmetallic materials. The further research would be produced a math model to describe the shadow effects of different features in the future work.

  7. Uniformity Masks Design Method Based on the Shadow Matrix for Coating Materials with Different Condensation Characteristics

    Directory of Open Access Journals (Sweden)

    Lichao Zhang

    2013-01-01

    Full Text Available An intuitionistic method is proposed to design shadow masks to achieve thickness profile control for evaporation coating processes. The proposed method is based on the concept of the shadow matrix, which is a matrix that contains coefficients that build quantitive relations between shape parameters of masks and shadow quantities of substrate directly. By using the shadow matrix, shape parameters of shadow masks could be derived simply by solving a matrix equation. Verification experiments were performed on a special case where coating materials have different condensation characteristics. By using the designed mask pair with complementary shapes, thickness uniformities of better than 98% are demonstrated for MgF2 ( and LaF3 ( simultaneously on a 280 mm diameter spherical substrate with the radius curvature of 200 mm.

  8. Shadow Probability of Detection and False Alarm for Median-Filtered SAR Imagery

    Energy Technology Data Exchange (ETDEWEB)

    Raynal, Ann Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). ISR Analysis and Applications Dept.; Doerry, Armin Walter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). ISR Mission Engineering Dept.; Miller, John A. [General Atomics Aeronautical Systems, Inc., San Diego, CA (United States). Mission Systems; Bishop, Edward E. [General Atomics Aeronautical Systems, Inc., San Diego, CA (United States). Mission Systems; Horndt, Volker [General Atomics Aeronautical Systems, Inc., San Diego, CA (United States). Mission Systems

    2014-06-01

    Median filtering reduces speckle in synthetic aperture radar (SAR) imagery while preserving edges, at the expense of coarsening the resolution, by replacing the center pixel of a sliding window by the median value. For shadow detection, this approach helps distinguish shadows from clutter more easily, while preserving shadow shape delineations. However, the nonlinear operation alters the shadow and clutter distributions and statistics, which must be taken into consideration when computing probability of detection and false alarm metrics. Depending on system parameters, median filtering can improve probability of detection and false alarm by orders of magnitude. Herein, we examine shadow probability of detection and false alarm in a homogeneous, ideal clutter background after median filter post-processing. Some comments on multi-look processing effects with and without median filtering are also made.

  9. Hawaii Leeward IKONOS and Quickbird Imagery - Mosaic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project is a cooperative effort between the National Ocean Service, National Centers for Coastal Ocean Science, Center for Coastal Monitoring and Assessment,...

  10. Measuring the CO2 shadow price for wastewater treatment: A directional distance function approach

    International Nuclear Information System (INIS)

    Molinos-Senante, María; Hanley, Nick; Sala-Garrido, Ramón

    2015-01-01

    Highlights: • The shadow price of CO 2 informs about the marginal abatement cost of this pollutant. • It is estimated the shadow price of CO 2 for wastewater treatment plants. • The shadow prices depend on the setting of the directional vectors of the distance function. • Sewage sludge treatment technology affects the CO 2 shadow price. - Abstract: The estimation of the value of carbon emissions has become a major research and policy topic since the establishment of the Kyoto Protocol. The shadow price of CO 2 provides information about the marginal abatement cost of this pollutant. It is an essential element in guiding environmental policy issues, since the CO 2 shadow price can be used when fixing carbon tax rates, in environmental cost-benefit analysis and in ascertaining an initial market price for a trading system. The water industry could play an important role in the reduction of greenhouse gas (GHG) emissions. This paper estimates the shadow price of CO 2 for a sample of wastewater treatment plants (WWTPs), using a parametric quadratic directional distance function. Following this, in a sensitivity analysis, the paper evaluates the impact of different settings of directional vectors on the shadow prices. Applying the Mann–Whitney and Kruskal–Wallis non-parametric tests, factors affecting CO 2 prices are investigated. The variation of CO 2 shadow prices across the WWTPs evaluated argues in favour of a market-based approach to CO 2 mitigation as opposed to command-and-control regulation. The paper argues that the estimation of the shadow price of CO 2 for non-power enterprises can provide incentives for reducing GHG emissions

  11. Fabrication of high-aspect-ratio nano structures using a nano x-ray shadow mask

    International Nuclear Information System (INIS)

    Kim, Yong Chul; Lee, Seung S

    2008-01-01

    This paper describes a novel method for the fabrication of high-aspect-ratio nano structures (HAR-nano structures) using a nano x-ray shadow mask and deep x-ray lithography (DXRL). The nano x-ray shadow mask is fabricated by depositing an x-ray absorber layer (Au, 3 µm) onto the back side of a nano shadow mask. The nano shadow mask is produced with nano-sized apertures whose dimensions are reduced to several tens of nanometers by the accumulation of low-stress silicon nitride (Si x N y ) using the LPCVD process on the shadow mask. A shadow mask containing apertures with a size of 1 µm is fabricated on a bulk micromachined Si x N y membrane. The thickness of an absorber layer must be in the range of several tens of micrometers in order to obtain a contrast of more than 100 for the conventional DXRL process at the Pohang Light Source (PLS). However, a 3 µm thick absorber layer can provide a sufficient contrast if the modified DXRL of the central beam-stop method is used, which blocks high-energy x-rays. A nano shadow mask with 30 nm sized apertures is fabricated and a nano x-ray shadow mask with 250 nm sized apertures is fabricated by depositing a 3 µm thick absorber layer on a nano shadow mask with 500 nm sized apertures. HAR-nano structures (circles with a diameter of 420 nm and lines with a width of 274 nm) with aspect ratios of over 10:1 on a 3.2 µm SU-8 are successfully fabricated by using the nano x-ray shadow mask and the central beam-stop method

  12. Perception of object motion in three-dimensional space induced by cast shadows.

    Science.gov (United States)

    Katsuyama, Narumi; Usui, Nobuo; Nose, Izuru; Taira, Masato

    2011-01-01

    Cast shadows can be salient depth cues in three-dimensional (3D) vision. Using a motion illusion in which a ball is perceived to roll in depth on the bottom or to flow in the front plane depending on the slope of the trajectory of its cast shadow, we investigated cortical mechanisms underlying 3D vision based on cast shadows using fMRI techniques. When modified versions of the original illusion, in which the slope of the shadow trajectory (shadow slope) was changed in 5 steps from the same one as the ball trajectory to the horizontal, were presented to participants, their perceived ball trajectory shifted gradually from rolling on the bottom to floating in the front plane as the change of the shadow slope. This observation suggests that the perception of the ball trajectory in this illusion is strongly affected by the motion of the cast shadow. In the fMRI study, cortical activity during observation of the movies of the illusion was investigated. We found that the bilateral posterior-occipital sulcus (POS) and right ventral precuneus showed activation related to the perception of the ball trajectory induced by the cast shadows in the illusion. Of these areas, it was suggested that the right POS may be involved in the inferring of the ball trajectory by the given spatial relation between the ball and the shadow. Our present results suggest that the posterior portion of the medial parietal cortex may be involved in 3D vision by cast shadows. Copyright © 2010 Elsevier Inc. All rights reserved.

  13. Rainforest metropolis casts 1,000-km defaunation shadow.

    Science.gov (United States)

    Tregidgo, Daniel J; Barlow, Jos; Pompeu, Paulo S; de Almeida Rocha, Mayana; Parry, Luke

    2017-08-08

    Tropical rainforest regions are urbanizing rapidly, yet the role of emerging metropolises in driving wildlife overharvesting in forests and inland waters is unknown. We present evidence of a large defaunation shadow around a rainforest metropolis. Using interviews with 392 rural fishers, we show that fishing has severely depleted a large-bodied keystone fish species, tambaqui ( Colossoma macropomum ), with an impact extending over 1,000 km from the rainforest city of Manaus (population 2.1 million). There was strong evidence of defaunation within this area, including a 50% reduction in body size and catch rate (catch per unit effort). Our findings link these declines to city-based boats that provide rural fishers with reliable access to fish buyers and ice and likely impact rural fisher livelihoods and flooded forest biodiversity. This empirical evidence that urban markets can defaunate deep into rainforest wilderness has implications for other urbanizing socioecological systems.

  14. Quarkonium plus prompt-photon associated hadroproduction and nuclear shadowing

    Energy Technology Data Exchange (ETDEWEB)

    Brenner Mariotto, C. [Universidade Federal do Rio Grande, Instituto de Matematica, Estatistica e Fisica, Caixa Postal 474, Rio Grande, RS (Brazil); Machado, M.V.T. [Universidade Federal do Pampa Campus de Bage, Centro de Ciencias Exatas e Tecnologicas, Bage, RS (Brazil)

    2010-06-15

    Quarkonium hadroproduction in association with a photon at high energies provides a probe of the dynamics of the strong interactions as it is dependent on the nuclear gluon distribution. Therefore, it could be used to constrain the behavior of the nuclear gluon distribution in proton-nucleus and nucleus-nucleus collisions. Such processes are useful to single out the magnitude of the shadowing/antishadowing effects in the nuclear parton densities. In this work we investigate the influence of nuclear effects in the production of J/{psi}+{gamma} and {upsilon}+{gamma} and estimate the transverse momentum dependence of the nuclear modification factors. The theoretical framework considered in the J/{psi} ({upsilon}) production associated with a direct photon at the hadron collider is the non-relativistic QCD (NRQCD) factorization formalism. (orig.)

  15. The Shadow of Big Data: Data-Citizenship and Exclusion

    DEFF Research Database (Denmark)

    Rossi, Luca; Hjelholt, Morten; Neumayer, Christina

    2016-01-01

    The shadow of Big Data: data-citizenship and exclusion Big data are understood as being able to provide insights on human behaviour at an individual as well as at an aggregated societal level (Manyka et al. 2011). These insights are expected to be more detailed and precise than anything before...... thanks to the large volume of digital data and to the unobstrusive nature of the data collection (Fishleigh 2014). Within this perspective, these two dimensions (volume and unobstrusiveness) define contemporary big data techniques as a socio-technical offering to society, a live representation of itself...... this process "data-citizenship" emerges. Data-citizenship assumes that citizens will be visible to the state through the data they produce. On a general level data-citizenship shifts citizenship from an intrinsic status of a group of people to a status achieved through action. This approach assumes equal...

  16. AN ANALYSIS OF THE SHADOW ECONOMY IN EU COUNTRIES

    Directory of Open Access Journals (Sweden)

    Brindusa Mihaela Tudose

    2016-08-01

    Full Text Available The paper aims at analysing the dimension of the underground economy in the EU states between 2003 and 2015. In order to achieve this goal, we use qualitative and quantitative methods. In the first two sections of the study we resort to conceptualisation and bring up to date scientific contributions in the field of the shadow economy both in terms of its definition and the methods of quantifying the phenomenon. In the third section, based on the results of the latest research, we identify the dynamics of the underground economy on three levels: the EU-15 (before and after 2005; the EU-10 (before and after the accession of 10 countries in 2005 and the EU-3 (before and after 2007. The main conclusion is that regardless of the reporting level (national, European, world, the real size of the underground economy remains unknown.

  17. Rainforest metropolis casts 1,000-km defaunation shadow

    Science.gov (United States)

    Tregidgo, Daniel J.; Barlow, Jos; Pompeu, Paulo S.; de Almeida Rocha, Mayana; Parry, Luke

    2017-01-01

    Tropical rainforest regions are urbanizing rapidly, yet the role of emerging metropolises in driving wildlife overharvesting in forests and inland waters is unknown. We present evidence of a large defaunation shadow around a rainforest metropolis. Using interviews with 392 rural fishers, we show that fishing has severely depleted a large-bodied keystone fish species, tambaqui (Colossoma macropomum), with an impact extending over 1,000 km from the rainforest city of Manaus (population 2.1 million). There was strong evidence of defaunation within this area, including a 50% reduction in body size and catch rate (catch per unit effort). Our findings link these declines to city-based boats that provide rural fishers with reliable access to fish buyers and ice and likely impact rural fisher livelihoods and flooded forest biodiversity. This empirical evidence that urban markets can defaunate deep into rainforest wilderness has implications for other urbanizing socioecological systems. PMID:28739913

  18. An experimental study of pressure shadows in partially molten rocks

    Science.gov (United States)

    Qi, Chao; Zhao, Yong-Hong; Kohlstedt, David L.

    2013-11-01

    As a two-phase, solid-melt material flows around rigid particles, melt-depleted and melt-enriched regions (i.e., pressure shadows) develop due to the coupled fluxes of melt and solid driven by pressure gradients around the particles. To study this compaction-decompaction process, samples composed of fine-grained San Carlos olivine plus mid-ocean ridge basalt containing dispersed sub-millimeter-sized, single crystal beads of olivine were deformed in torsion at a temperature of 1473 K and a confining pressure of 300 MPa. Indicated by melt distribution maps obtained from reflected-light optical and backscattered electron microscopy, melt-enriched and melt-depleted regions around the beads became observable at a local shear strain of γ≈1 in samples with an initially homogeneously distributed melt fraction of ϕ≈0.05. The melt-enriched regions (ϕbarhigh≈0.06 to 0.10) and the melt-depleted regions (ϕbarlow≈0.02 to 0.04), extending as far as one radius of the bead, were symmetrically distributed around the bead. The flow field of the olivine matrix determined from crystallographic preferred orientations agrees with theoretical predictions based on two-phase flow analysis. These experiments are the first to produce pressure shadows in partially molten rocks. One implication of this study is that it will be possible to constrain the ratio of bulk to shear viscosity, which is inferred from the distribution of melt using a combination of experimental observations and numerical simulations.

  19. Detection and tracking of moving objects under occlusion and shadow

    Science.gov (United States)

    Ming, Ying; Jiang, Jingjue

    2005-10-01

    This paper presents a system to detect and track multiple moving objects in the presence of mutual occlusion and shadow. A novel change detection algorithm based on Cauchy distribution is proposed. The ratio of pixel's intensities between two images is used as the feature to model and subtract background. The distribution of the ratio of background pixel's intensities between a current image and a reference image can obeys Cauchy distribution, assumed that some observed temporal intensity variation of each pixel in a background image is caused by white noise. By hypothesis testing whose decision thresholds are related to the false alarm rate, robust change detection can be carried out. We exploit spectral and geometrical properties of shadows to recognize and eliminate them in video sequences. Intensity, hue and saturation in the YCbCr color space is employed to this end. In order to solve ambiguity due to occlusion and recover from intermittent tracking failure, we propose a method to implement tracking of multiple moving objects. The method is based on multi-cue and dynamic templates matching in consecutive frames and motion estimation by Kalman filter. In our system, a fast accurate clustering algorithm based on k-nearest neighbor search is employed and the feature space is constructed by extracting the position, color, shape and velocity information of moving objects. In this paper, occlusions are addressed in two classes, i.e. static occlusion and dynamic occlusion. Depend on the prior knowledge of the background scene and the feedback from objects detection and tracking, the distribution of static occlusion region in the scene can be acquired and updated. The bounding box around a static occlusion region is used as an alarm sign to start the process of static occlusion. Dynamic occlusion event can be detected and processed in terms of the proposed tracking scheme and multi-cue and dynamic templates matching approach. Experiment results demonstrate that the

  20. Improvement of system of corporate management organs by forming shadow board

    Directory of Open Access Journals (Sweden)

    V.P. Holiver

    2017-08-01

    Full Text Available The article determines that the current existing system of corporate management organs of ajoint-stock company needs improvement in the direction of preparation of labour reserve. The expediency of forming labour reserve by board of directors in the joint-stock company is considered by the improvement of the system of corporate management organs and forming in its composition an alternative organ called a shadow board. The article determines that the activity of board of directors is carried out on the basis of conservative strategy, which consists of a careful conduct at the acceptance of administrative decisions. It is set that the activity of bord of directors is conservative from dependence on shareholders who appoint them. The paper proves the efficiency of combination of conservative strategy of making decision suggested by the board of directors with the aggressive strategy of the alternative organ, which must be the prototype of board of directors, but it must operate within the limits of aggressive strategy. It is proved that the synergy of conservative and aggressive strategy of forming suggestions by the board of directors of the joint-stock company with the use of additional working organ (shadow board will bring an effect. The effect from such synergy is the upgrading of making decisions by the board of directors. The place of shadow board in the system of corporate management organs is outlined. The analogy of shadow board’s activity similar to the activity of board of directors of the joint-stock company is shown. The features of co-operation of board of directors and shadow board are marked. The features of forming committees as a part of a shadow board and a general committee with a board of directors are outlined. The article deals with the key role of the shadow board in the preparation of skilled reserve of board of directors of the joint-stock company and in providing more aggressive strategy for making decisions. The

  1. Shock waves in water at low energy pulsed electric discharges

    International Nuclear Information System (INIS)

    Pinchuk, M E; Kolikov, V A; Rutberg, Ph G; Leks, A G; Dolinovskaya, R V; Snetov, V N; Stogov, A Yu

    2012-01-01

    Experimental results of shock wave formation and propagation in water at low energy pulsed electric discharges are presented. To study the hydrodynamic structure of the shock waves, the direct shadow optical diagnostic device with time resolution of 5 ns and spatial resolution of 0.1 mm was designed and developed. Synchronization of the diagnostic and electrodischarge units by the fast optocouplers was carried out. The dependences of shock wave velocities after breakdown of interelectrode gap for various energy inputs (at range of ≤1 J) into discharge were obtained. Based on the experimental results the recommendations for the adjustment parameters of the power supply and load were suggested.

  2. Numerical prediction of wave impact loads on multiple rectangular beams

    DEFF Research Database (Denmark)

    Mayer, Stefan; Nielsen, Kristian Bendix; Hansen, E.A.

    2005-01-01

    Wave impact on one and two structural beams with rectangular cross section is simulated with a two-dimensional finite volume method, solving the unsteady Euler equations and employing a VOF-type method for the description of the free surface. Four different test series are carried out, each...... corresponding to a wave impact scenario in the experimental database of Sterndorff [2002]. For the case of wave impact on a single structural element the numerical results show good agreement with measured force time histories. In the computations featuring two beams, the prediction of the shadowing effect...

  3. Controls of multi-modal wave conditions in a complex coastal setting

    Science.gov (United States)

    Hegermiller, Christie; Rueda, Ana C.; Erikson, Li H.; Barnard, Patrick L.; Antolinez, J.A.A.; Mendez, Fernando J.

    2017-01-01

    Coastal hazards emerge from the combined effect of wave conditions and sea level anomalies associated with storms or low-frequency atmosphere-ocean oscillations. Rigorous characterization of wave climate is limited by the availability of spectral wave observations, the computational cost of dynamical simulations, and the ability to link wave-generating atmospheric patterns with coastal conditions. We present a hybrid statistical-dynamical approach to simulating nearshore wave climate in complex coastal settings, demonstrated in the Southern California Bight, where waves arriving from distant, disparate locations are refracted over complex bathymetry and shadowed by offshore islands. Contributions of wave families and large-scale atmospheric drivers to nearshore wave energy flux are analyzed. Results highlight the variability of influences controlling wave conditions along neighboring coastlines. The universal method demonstrated here can be applied to complex coastal settings worldwide, facilitating analysis of the effects of climate change on nearshore wave climate.

  4. Frustum-Traced Irregular Z-Buffers: Fast, Sub-pixel Accurate Hard Shadows.

    Science.gov (United States)

    Wyman, Chris; Hoetzlein, Rama; Lefohn, Aaron

    2016-05-25

    We further describe and analyze a real-time system for rendering antialiased hard shadows using irregular z-buffers (IZBs) that we first presented in Wyman et al. [1]. We focus on identifying bottlenecks, exploring these from an algorithmic complexity standpoint, and presenting techniques to improve performance. Our system remains interactive on a variety of game assets and CAD models while running at resolutions 1920 1080 and above and imposes no constraints on light, camera or geometry, allowing fully dynamic scenes without precomputation. We render sub-pixel accurate, 32 sample per pixel hard shadows at roughly twice the cost of a single sample per pixel. This allows us to smoothly animate even subpixel shadows from grass or wires without introducing spatial or temporal aliasing. Prior algorithms for irregular z-buffer shadows rely heavily on the GPU's compute pipeline. Instead we leverage the standard rasterization-based graphics pipeline, including hardware conservative raster and early-z culling. Our key observation is noting a duality between irregular z-buffer performance and shadow map quality; irregular z-buffering is most costly exactly where shadow maps exhibit the worst aliasing. This allows us to use common shadow map algorithms, which typically improve aliasing, to instead reduce our cost. Compared to state of the art ray tracers, we spawn similar numbers of triangle intersections per pixel yet completely rebuild our data structure in under 1 ms per frame.

  5. An IMU-Aided Body-Shadowing Error Compensation Method for Indoor Bluetooth Positioning.

    Science.gov (United States)

    Deng, Zhongliang; Fu, Xiao; Wang, Hanhua

    2018-01-20

    Research on indoor positioning technologies has recently become a hotspot because of the huge social and economic potential of indoor location-based services (ILBS). Wireless positioning signals have a considerable attenuation in received signal strength (RSS) when transmitting through human bodies, which would cause significant ranging and positioning errors in RSS-based systems. This paper mainly focuses on the body-shadowing impairment of RSS-based ranging and positioning, and derives a mathematical expression of the relation between the body-shadowing effect and the positioning error. In addition, an inertial measurement unit-aided (IMU-aided) body-shadowing detection strategy is designed, and an error compensation model is established to mitigate the effect of body-shadowing. A Bluetooth positioning algorithm with body-shadowing error compensation (BP-BEC) is then proposed to improve both the positioning accuracy and the robustness in indoor body-shadowing environments. Experiments are conducted in two indoor test beds, and the performance of both the BP-BEC algorithm and the algorithms without body-shadowing error compensation (named no-BEC) is evaluated. The results show that the BP-BEC outperforms the no-BEC by about 60.1% and 73.6% in terms of positioning accuracy and robustness, respectively. Moreover, the execution time of the BP-BEC algorithm is also evaluated, and results show that the convergence speed of the proposed algorithm has an insignificant effect on real-time localization.

  6. An IMU-Aided Body-Shadowing Error Compensation Method for Indoor Bluetooth Positioning

    Directory of Open Access Journals (Sweden)

    Zhongliang Deng

    2018-01-01

    Full Text Available Research on indoor positioning technologies has recently become a hotspot because of the huge social and economic potential of indoor location-based services (ILBS. Wireless positioning signals have a considerable attenuation in received signal strength (RSS when transmitting through human bodies, which would cause significant ranging and positioning errors in RSS-based systems. This paper mainly focuses on the body-shadowing impairment of RSS-based ranging and positioning, and derives a mathematical expression of the relation between the body-shadowing effect and the positioning error. In addition, an inertial measurement unit-aided (IMU-aided body-shadowing detection strategy is designed, and an error compensation model is established to mitigate the effect of body-shadowing. A Bluetooth positioning algorithm with body-shadowing error compensation (BP-BEC is then proposed to improve both the positioning accuracy and the robustness in indoor body-shadowing environments. Experiments are conducted in two indoor test beds, and the performance of both the BP-BEC algorithm and the algorithms without body-shadowing error compensation (named no-BEC is evaluated. The results show that the BP-BEC outperforms the no-BEC by about 60.1% and 73.6% in terms of positioning accuracy and robustness, respectively. Moreover, the execution time of the BP-BEC algorithm is also evaluated, and results show that the convergence speed of the proposed algorithm has an insignificant effect on real-time localization.

  7. SHADOW EFFECT ON PHOTOVOLTAIC POTENTIALITY ANALYSIS USING 3D CITY MODELS

    Directory of Open Access Journals (Sweden)

    N. Alam

    2012-07-01

    Full Text Available Due to global warming, green-house effect and various other drawbacks of existing energy sources, renewable energy like Photovoltaic system is being popular for energy production. The result of photovoltaic potentiality analysis depends on data quality and parameters. Shadow rapidly decreases performance of the Photovoltaic system and it always changes due to the movement of the sun. Solar radiation incident on earth's atmosphere is relatively constant but the radiation at earth's surface varies due to absorption, scattering, reflection, change in spectral content, diffuse component, water vapor, clouds and pollution etc. In this research, it is being investigated that how efficiently real-time shadow can be detected for both direct and diffuse radiation considering reflection and other factors in contrast with the existing shadow detection methods using latest technologies and what is the minimum quality of data required for this purpose. Of course, geometric details of the building geometry and surroundings directly affect the calculation of shadows. In principle, 3D city models or point clouds, which contain roof structure, vegetation, thematically differentiated surface and texture, are suitable to simulate exact real-time shadow. This research would develop an automated procedure to measure exact shadow effect from the 3D city models and a long-term simulation model to determine the produced energy from the photovoltaic system. In this paper, a developed method for detecting shadow for direct radiation has been discussed with its result using a 3D city model to perform a solar energy potentiality analysis.

  8. Generalization of dependence between shadow radiation image and intensity of pulses at scanning detector output

    International Nuclear Information System (INIS)

    Nedavnij, O.I.; Udod, V.A.

    2000-01-01

    Dependence of general character is determined between shadow radiation image in nondestructive testing and intensity of electric pulse occasional flux observed at the detector output of testing radiometric system. Model for radiometric system detector operation in counting regime of radiation detection is derived. The model simultaneously accounts: possibility of scanning shadow radiation image of tested object (TO) by unspecified raster, possibility of using detectors with nonuniform spatial radiation sensitivity, effect of shadow radiation TO image averaging by detector in two-dimensional variant. This fact permits to investigate the maximum potential capabilities of radiation testing radiometric systems [ru

  9. Use of Shadowing-Based Learning in an Allied Health Microbiology Course

    Directory of Open Access Journals (Sweden)

    Alex A. Lowrey

    2016-05-01

    Full Text Available Students in an undergraduate microbiology course for health professions majors perform a shadowing-based learning exercise for their course project. Students accomplish this by shadowing a health care professional of their choice, specifically incorporating basic microbiological concept themes into their observations. These concept themes include the biological nature, health effects, detection, and control of microorganisms. Upon completion of the shadowing experience, students present a concise report, which is graded on how well the students connect course scientific concepts with actual clinical practice.

  10. A trial of selective imaging for the breast mass shadow by computed radiography

    International Nuclear Information System (INIS)

    Muramatsu, Yukio; Anan, Mitsuhiro; Tanaka, Takashi; Matsue, Hiroto; Yamada, Tatsuya

    1990-01-01

    CR has ability to make many kinds of images by several imaging processings. Especially, gradation processing is more important than frequency processing to make images in CR mammography. We developed new method to image breast masses selectively with new gradation processing and tried it for 18 patients over sixty years old with breast cancer. All of breast mass shadows were separated selectively from other parencymal shadow. So, we conclude that the auto-recognition of breast mass shadow can be possible in near future in CR system. (author)

  11. Shapes and Positions of Black Hole Shadows in Accretion Disks and Spin Parameters of Black Holes

    OpenAIRE

    Takahashi, Rohta

    2004-01-01

    Can we determine a spin parameter of a black hole by observation of a black hole shadow in an accretion disk? In order to answer this question, we make a qualitative analysis and a quantitative analysis of a shape and a position of a black hole shadow casted by a rotating black hole on an optically thick accretion disk and its dependence on an angular momentum of a black hole. We have found black hole shadows with a quite similar size and a shape for largely different black hole spin paramete...

  12. Cold Nuclear Matter effects on J/psi production at RHIC: comparing shadowing models

    Energy Technology Data Exchange (ETDEWEB)

    Ferreiro, E.G.; /Santiago de Compostela U.; Fleuret, F.; /Ecole Polytechnique; Lansberg, J.P.; /SLAC; Rakotozafindrabe, A.; /SPhN, DAPNIA, Saclay

    2009-06-19

    We present a wide study on the comparison of different shadowing models and their influence on J/{psi} production. We have taken into account the possibility of different partonic processes for the c{bar c}-pair production. We notice that the effect of shadowing corrections on J/{psi} production clearly depends on the partonic process considered. Our results are compared to the available data on dAu collisions at RHIC energies. We try different break up cross section for each of the studied shadowing models.

  13. Waiting for Shadows from the Distant Solar System

    Science.gov (United States)

    Kohler, Susanna

    2016-03-01

    How can we hope to measure the hundreds of thousands of objects in our distant solar system? A team of astronomers is harnessing citizen science to begin to tackle this problem!A light curve from an occultation collected by a RECON site in Quincy, California. As the objects shadow passes, the background stars light dims. [RECON/Charley Arrowsmith (Feather River College)]Occultation InformationEstimates currently place the number of Kuiper belt objects larger than 100 km across at over 100,000. Knowing the sizes and characteristics of these objects is important for understanding the composition of the outer solar system and constraining models of the solar systems formation and evolution.Unfortunately, measuring small, dim bodies at large distances is incredibly difficult! One of the best ways to obtain the sizes of these objects is to watch as they occult a distant star. Timing the object as it passes across the face of the star can give us a good measure of its size and shape, when observed from multiple stations in the path of the shadow.An Extended NetworkOccultations by nearby objects (like main-belt asteroids) can be predicted fairly accurately, but those by trans-Neptunian objects are much more poorly constrained. Only ~900 trans-Neptunian objects have approximately known paths, and occultation-shadow predictions for these objects are often only accurate to ~1000km on the Earths surface. So how can we ensure that theres a telescope in the right location, ready to observe when an occultation occurs?Map of the 56 RECON sites distributed over 2000 km in the western United States. [Buie et al. 2016]The simplest answer is to set up a huge network of observing stations, and wait for the shadows to come to the network. With this approach, even if the predicted path isnt precisely known, some of the stations will still observe the occultation.Due to the number of stations needed, this project lends itself perfectly to citizen science. In a recently published paper by

  14. In vitro study of the erbium:yttrium aluminum garnet laser cleaning of root canal by the use of shadow photography

    Science.gov (United States)

    Gregorčič, Peter; Lukač, Nejc; Možina, Janez; Jezeršek, Matija

    2016-01-01

    Erbium:yttrium aluminum garnet laser cleaning is a promising technique in endodontic treatment. In our in vitro study, we measured the vapor-bubble dynamics in the root canal by using shadow photography. The canal model was made of a plastic cutout placed between two transparent glass plates. An artificial smear layer was applied to the glass to study cleaning efficiency. In our results, no shock waves have been observed, since the pulp-chamber dimensions have been in the same range as the maximum diameter of the vapor bubble. This leads to the conclusion that shock waves are not the main cleaning mechanism within our model. However, the cleaning effects are also visible in the regions significantly below the bubble. Therefore, it can be concluded that fluid flow induced by the bubble's oscillations contributes significantly to the canal cleaning. We also proposed a simple theoretical model for cleaning efficiency and used it to evaluate the measured data.

  15. Color fluctuation approximation for multiple interactions in leading twist theory of nuclear shadowing

    Energy Technology Data Exchange (ETDEWEB)

    Vadim Guzey, Mark Strikman

    2010-04-01

    The leading twist theory of nuclear shadowing predicts nuclear parton distributions in the small $x$ shadowing region by connecting them to the leading twist hard diffraction in electron-nucleon scattering. The uncertainties of the predictions are related to the shadowing effects resulting from the interaction of the hard probe with $N \\ge 3$ nucleons. We argue that the pattern of hard diffraction observed at HERA allows one to reduce these uncertainties, and we develop a new approach to the treatment of these multiple collisions. It is based on the concept of the color fluctuations and accounts for the presence of both point-like and hadron-like configurations in the virtual photon. Using the developed framework, we update our predictions for the effect of the leading twist nuclear shadowing in nuclear parton distributions of heavy nuclei at small $x$.

  16. A circuit-based photovoltaic module simulator with shadow and fault settings

    Science.gov (United States)

    Chao, Kuei-Hsiang; Chao, Yuan-Wei; Chen, Jyun-Ping

    2016-03-01

    The main purpose of this study was to develop a photovoltaic (PV) module simulator. The proposed simulator, using electrical parameters from solar cells, could simulate output characteristics not only during normal operational conditions, but also during conditions of partial shadow and fault conditions. Such a simulator should possess the advantages of low cost, small size and being easily realizable. Experiments have shown that results from a proposed PV simulator of this kind are very close to that from simulation software during partial shadow conditions, and with negligible differences during fault occurrence. Meanwhile, the PV module simulator, as developed, could be used on various types of series-parallel connections to form PV arrays, to conduct experiments on partial shadow and fault events occurring in some of the modules. Such experiments are designed to explore the impact of shadow and fault conditions on the output characteristics of the system as a whole.

  17. SHADOW ECONOMY AND ITS RELATIONS WITH TAX SYSTEM, BUDGET DEFICIT AND MACROECONOMIC INDICATORS

    Directory of Open Access Journals (Sweden)

    I. Savych

    2015-03-01

    Full Text Available The paper analyzes the influence of the shadow economy on the tax system, state budget and a number of macroeconomic parameters of Ukraine such as poverty, income levels, corruption, GDP per capita, public debt, budget violations etc. The results of our research show that level of corruption, monopolization and budget violations are considered key factors that stimulate the shadowing of the economy. On the other hand, a number of researchers state that the average wage level is a strong destimulating factor for the shadow economy. The analysis given uncovers a robust relationship between the corruption and the size of the shadow economy when perceptions-based indices of corruption are used.

  18. Political negotiation and co-operation in the shadow of public discourse

    OpenAIRE

    Viehöver, Willy

    2000-01-01

    Political negotiation and co-operation in the shadow of public discourse : the formation of the German waste management system DSD (Dual System Germany) as a case study. - In: European Environment. 10. 2000. S. 277-292

  19. Reduction of implantation shadowing effect by dual-wavelength exposure photo process

    CERN Document Server

    Gu, Yiming; Lee Sang Yun; Roche, William; Sturtevant, John

    2003-01-01

    As transistor engineering continues to well below 100 nm length devices, ion implantation process tolerances are making these formerly "non-critical" lithography levels more and more difficult. In order to minimize the channeling effect and to obtain a controllable profile of dopant, an angle implantation is often required. However, a shadow area of resist pattern is always accompanied with an angle implantation. This shadowing effect consumes silicon real estate, and reduces the line edge placement (LEP) tolerances. Therefore, methodologies to reduce the shadowing effect in angled implantation become a critical consideration not only for device engineering but also for photolithography. Based on the model analysis, simulation and experiments, this paper presents an effective novel process utilizing dual-wavelength exposure (DWE) to reduce the shadowing effect. The DWE process is realized by two consecutive exposures for an I-line resist with a DUV stepper/scanner and an I-line stepper. The process leverages ...

  20. The effects of shadow removal on across-date settlement type classification of quickbird images

    CSIR Research Space (South Africa)

    Luus, FPS

    2012-07-01

    Full Text Available QuickBird imagery acquired on separate dates may have significant differences in viewing- and illumination geometries, which can negatively impact across-date settlement type classification accuracy. The effect of cast shadows on classification...

  1. Leading twist nuclear shadowing, nuclear generalized parton distributions and nuclear DVCS at small x

    Energy Technology Data Exchange (ETDEWEB)

    Guzey, Vadim; Goeke, Klaus; Siddikov, Marat

    2009-01-01

    We generalize the leading twist theory of nuclear shadowing and calculate quark and gluon generalized parton distributions (GPDs) of spinless nuclei. We predict very large nuclear shadowing for nuclear GPDs. In the limit of the purely transverse momentum transfer, our nuclear GPDs become impact parameter dependent nuclear parton distributions (PDFs). Nuclear shadowing induces non-trivial correlations between the impact parameter $b$ and the light-cone fraction $x$. We make predictions for the deeply virtual Compton scattering (DVCS) amplitude and the DVCS cross section on $^{208}$Pb at high energies. We calculate the cross section of the Bethe-Heitler (BH) process and address the issue of the extraction of the DVCS signal from the $e A \\to e \\gamma A$ cross section. We find that the $e A \\to e \\gamma A$ differential cross section is dominated by DVCS at the momentum transfer $t$ near the minima of the nuclear form factor. We also find that nuclear shadowing leads

  2. "JOB SEEKER"(Job Shadowing for Employee Engagement through Knowledge and Experience Retention).

    Science.gov (United States)

    2016-05-01

    The main objective of this study was to explore how to optimally use the particular knowledge : retention/transfer technique of job shadowing as an informal method for knowledge capture and : transfer as well as increasing communication and emp...

  3. Rough surfaces: Is the dark stuff just shadow?. ;Who knows what evil lurks in the hearts of men? The shadow knows!;☆

    Science.gov (United States)

    Cuzzi, Jeffrey N.; Chambers, Lindsey B.; Hendrix, Amanda R.

    2017-06-01

    Remote observations of the surfaces of airless planetary objects are fundamental to inferring the physical structure and compositional makeup of the surface material. A number of forward models have been developed to reproduce the photometric behavior of these surfaces, based on specific, assumed structural properties such as macroscopic roughness and associated shadowing. Most work of this type is applied to geometric albedos, which are affected by complicated effects near zero phase angle that represent only a tiny fraction of the net energy reflected by the object. Other applications include parameter fits to resolved portions of some planetary surface as viewed over a range of geometries. The spherical albedo of the entire object (when it can be determined) captures the net energy balance of the particle more robustly than the geometric albedo. In most treatments involving spherical albedos, spherical albedos and particle phase functions are often treated as if they are independent, neglecting the effects of roughness. In this paper we take a different approach. We note that whatever function captures the phase angle dependence of the brightness of a realistic rough, shadowed, flat surface element relative to that of a smooth granular surface of the same material, it is manifested directly in both the integral phase function and the spherical albedo of the object. We suggest that, where broad phase angle coverage is possible, spherical albedos may be easily corrected for the effects of shadowing using observed (or assumed) phase functions, and then modeled more robustly using smooth-surface regolith radiative transfer models without further imposed (forward-modeled) shadowing corrections. Our approach attributes observed "powerlaw" phase functions of various slope (and "linear" ranges of magnitude-vs.-phase angle) to shadowing, as have others, and goes in to suggest that regolith-model-based inferences of composition based on shadow-uncorrected spherical

  4. Wave turbulence

    Science.gov (United States)

    Nazarenko, Sergey

    2015-07-01

    Wave turbulence is the statistical mechanics of random waves with a broadband spectrum interacting via non-linearity. To understand its difference from non-random well-tuned coherent waves, one could compare the sound of thunder to a piece of classical music. Wave turbulence is surprisingly common and important in a great variety of physical settings, starting with the most familiar ocean waves to waves at quantum scales or to much longer waves in astrophysics. We will provide a basic overview of the wave turbulence ideas, approaches and main results emphasising the physics of the phenomena and using qualitative descriptions avoiding, whenever possible, involved mathematical derivations. In particular, dimensional analysis will be used for obtaining the key scaling solutions in wave turbulence - Kolmogorov-Zakharov (KZ) spectra.

  5. Extended Kalman Filtering and Pathloss modeling for Shadow Power Parameter Estimation in Mobile Wireless Communications

    OpenAIRE

    P. Pappas, George; A. Zohdy, Mohamed

    2017-01-01

    In this paper accurate estimation of parameters, higher order state space prediction methods and Extended Kalman filter (EKF) for modeling shadow power in wireless mobile communications are developed. Path-loss parameter estimation models are compared and evaluated. Shadow power estimation methods in wireless cellular communications are very important for use in power control of mobile device and base station. The methods are validated and compared to existing methods, Kalman Filter (KF) with...

  6. Segmentation of Shadowed Buildings in Dense Urban Areas from Aerial Photographs

    OpenAIRE

    Susaki, Junichi

    2012-01-01

    Segmentation of buildings in urban areas, especially dense urban areas, by using remotely sensed images is highly desirable. However, segmentation results obtained by using existing algorithms are unsatisfactory because of the unclear boundaries between buildings and the shadows cast by neighboring buildings. In this paper, an algorithm is proposed that successfully segments buildings from aerial photographs, including shadowed buildings in dense urban areas. To handle roofs having rough text...

  7. The medial oblique foot x-ray: identification of soft tissue shadows seen plantarly.

    Science.gov (United States)

    Lieber, G A

    1983-01-01

    A soft tissue shadow is present on oblique foot x-rays in the arc between the lateral process of the calcaneus and the styloid process of the fifth metatarsal. Surgical placement of metal wires, followed by x-ray examination, has conclusively shown the shadow to have two components, namely, the tendon of peroneus longus and the muscle belly and tendon of abductor digiti minimi. Double screen intensifying cassettes are highly recommended to obtain soft tissue resolution.

  8. Load-cell based characterization system for a "Violin-Mode" shadow-sensor in advanced LIGO suspensions.

    Science.gov (United States)

    Lockerbie, N A; Tokmakov, K V

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which 40 kg test-mass/mirrors are each suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation and a rectangular silicon photodiode detector, which, together, were to bracket the fibre under test. The aim was to detect transverse Violin-Mode resonances in the suspension fibres. Part of the testing procedure involved tensioning a silica fibre sample and translating it transversely through the illuminating NIR beam, so as to measure the DC responsivity of the detection system to fibre displacement. However, an equally important part of the procedure, reported here, was to keep the fibre under test stationary within the beam, whilst trying to detect low-level AC Violin-Mode resonances excited on the fibre, in order to confirm the primary function of the sensor. Therefore, a tensioning system, incorporating a load-cell readout, was built into the test fibre's holder. The fibre then was excited by a signal generator, audio power amplifier, and distant loudspeaker, and clear resonances were detected. A theory for the expected fundamental resonant frequency as a function of fibre tension was developed and is reported here, and this theory was found to match closely with the detected resonant frequencies as they varied with tension. Consequently, the resonances seen were identified as being proper Violin-Mode fundamental resonances of the fibre, and the operation of the Violin-Mode detection system was validated.

  9. Load-cell based characterization system for a “Violin-Mode” shadow-sensor in advanced LIGO suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Lockerbie, N. A.; Tokmakov, K. V. [SUPA (Scottish Universities Physics Alliance) Department of Physics, University of Strathclyde, 107 Rottenrow, Glasgow G4 0NG (United Kingdom)

    2016-07-15

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which 40 kg test-mass/mirrors are each suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation and a rectangular silicon photodiode detector, which, together, were to bracket the fibre under test. The aim was to detect transverse Violin-Mode resonances in the suspension fibres. Part of the testing procedure involved tensioning a silica fibre sample and translating it transversely through the illuminating NIR beam, so as to measure the DC responsivity of the detection system to fibre displacement. However, an equally important part of the procedure, reported here, was to keep the fibre under test stationary within the beam, whilst trying to detect low-level AC Violin-Mode resonances excited on the fibre, in order to confirm the primary function of the sensor. Therefore, a tensioning system, incorporating a load-cell readout, was built into the test fibre’s holder. The fibre then was excited by a signal generator, audio power amplifier, and distant loudspeaker, and clear resonances were detected. A theory for the expected fundamental resonant frequency as a function of fibre tension was developed and is reported here, and this theory was found to match closely with the detected resonant frequencies as they varied with tension. Consequently, the resonances seen were identified as being proper Violin-Mode fundamental resonances of the fibre, and the operation of the Violin-Mode detection system was validated.

  10. Load-cell based characterization system for a "Violin-Mode" shadow-sensor in advanced LIGO suspensions

    Science.gov (United States)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-07-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which 40 kg test-mass/mirrors are each suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation and a rectangular silicon photodiode detector, which, together, were to bracket the fibre under test. The aim was to detect transverse Violin-Mode resonances in the suspension fibres. Part of the testing procedure involved tensioning a silica fibre sample and translating it transversely through the illuminating NIR beam, so as to measure the DC responsivity of the detection system to fibre displacement. However, an equally important part of the procedure, reported here, was to keep the fibre under test stationary within the beam, whilst trying to detect low-level AC Violin-Mode resonances excited on the fibre, in order to confirm the primary function of the sensor. Therefore, a tensioning system, incorporating a load-cell readout, was built into the test fibre's holder. The fibre then was excited by a signal generator, audio power amplifier, and distant loudspeaker, and clear resonances were detected. A theory for the expected fundamental resonant frequency as a function of fibre tension was developed and is reported here, and this theory was found to match closely with the detected resonant frequencies as they varied with tension. Consequently, the resonances seen were identified as being proper Violin-Mode fundamental resonances of the fibre, and the operation of the Violin-Mode detection system was validated.

  11. Load-cell based characterization system for a “Violin-Mode” shadow-sensor in advanced LIGO suspensions

    International Nuclear Information System (INIS)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-01-01

    The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which 40 kg test-mass/mirrors are each suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation and a rectangular silicon photodiode detector, which, together, were to bracket the fibre under test. The aim was to detect transverse Violin-Mode resonances in the suspension fibres. Part of the testing procedure involved tensioning a silica fibre sample and translating it transversely through the illuminating NIR beam, so as to measure the DC responsivity of the detection system to fibre displacement. However, an equally important part of the procedure, reported here, was to keep the fibre under test stationary within the beam, whilst trying to detect low-level AC Violin-Mode resonances excited on the fibre, in order to confirm the primary function of the sensor. Therefore, a tensioning system, incorporating a load-cell readout, was built into the test fibre’s holder. The fibre then was excited by a signal generator, audio power amplifier, and distant loudspeaker, and clear resonances were detected. A theory for the expected fundamental resonant frequency as a function of fibre tension was developed and is reported here, and this theory was found to match closely with the detected resonant frequencies as they varied with tension. Consequently, the resonances seen were identified as being proper Violin-Mode fundamental resonances of the fibre, and the operation of the Violin-Mode detection system was validated.

  12. Glacial isostatic stress shadowing by the Antarctic ice sheet

    Science.gov (United States)

    Ivins, E. R.; James, T. S.; Klemann, V.

    2005-01-01

    Numerous examples of fault slip that offset late Quaternary glacial deposits and bedrock polish support the idea that the glacial loading cycle causes earthquakes in the upper crust. A semianalytical scheme is presented for quantifying glacial and postglacial lithospheric fault reactivation using contemporary rock fracture prediction methods. It extends previous studies by considering differential Mogi-von Mises stresses, in addition to those resulting from a Coulomb analysis. The approach utilizes gravitational viscoelastodynamic theory and explores the relationships between ice mass history and regional seismicity and faulting in a segment of East Antarctica containing the great Antarctic Plate (Balleny Island) earthquake of 25 March 1998 (Mw 8.1). Predictions of the failure stress fields within the seismogenic crust are generated for differing assumptions about background stress orientation, mantle viscosity, lithospheric thickness, and possible late Holocene deglaciation for the D91 Antarctic ice sheet history. Similar stress fracture fields are predicted by Mogi-von Mises and Coulomb theory, thus validating previous rebound Coulomb analysis. A thick lithosphere, of the order of 150-240 km, augments stress shadowing by a late melting (middle-late Holocene) coastal East Antarctic ice complex and could cause present-day earthquakes many hundreds of kilometers seaward of the former Last Glacial Maximum grounding line.

  13. INNOVATIVE PRACTICES IN TOURISM. APOSSIBLE MODEL BY FOSTERING SHADOW FACTORS

    Directory of Open Access Journals (Sweden)

    Ada Mirela TOMESCU

    2015-08-01

    Full Text Available The paper is the result of an empirical research, a study that includes a theoretical framework. The data used to test our hypotheses come from 60 small tourism firms from Bihor County, Romania. The research conducted has revealed that actions focusing on innovation must be based on a solid analysis, supported by the knowledge and the understanding of the contextual factors (environment, culture as a mental programming, values also based on the organizational factors (the management commitment, systemic perspective, learning and practice of experimentation, rapid transfer of knowledge within the organization. For the purpose of this work, the contextual factors that are exogenous represent the shadow factors. The studies performed in three European projects implemented in tourism SMEs of Bihor County have allowed us to advance the idea that contextual and organizational factors, that are identified as the source of innovation are based on rationality, which is enlarged by affectivity and imagination. The identified correlations may be considered, in our opinion an element of novelty and originality. Finally, the purpose of this paper is to provide a possible model, based on the idea of building an innovative firm, the one that has learned how to determine their own employees to be innovative. O03, L2, L26

  14. Mappe transizionali in Shadow Lines. Response a Silvia Albertazzi

    Directory of Open Access Journals (Sweden)

    Marina Guglielmi

    2011-06-01

    Full Text Available My response to Silvia Albertazzi’s paper on The Shadow Lines by Amitav Ghosh focuses on a key element of the discourse: the function and use of the map in the definition of subjectivity. The first step I take is to identify the presence of a relationship between the individual subject and that of the collective in Ghosh’s novel. From there forward, the relationship between real and imaginary becomes critical to the analysis of the question of the construction of the self in the narrator. The real/imaginary dichotomy acquires meaning when placed in contact with the notion of the borders lying between the external world and the internal world. The concept of the Transitional Object developed by Donald W. Winnicott is used in this context to formulate the hypothesis of representation in the Ghosh’s novel, of transitional maps which facilitate the passage of the character of the internal world (the self to the external world (the non-me. Using maps such as these, the narrative representation of the connection between internal space and external space contributes to the literary construction of the physical features of the individual subject.

  15. Plasma waves

    CERN Document Server

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  16. Physics from the Milagro observation of Cosmic-Ray Shadows of the Moon and Sun

    Science.gov (United States)

    Christopher, Grant

    2009-05-01

    Preliminary results will be presented on studies of the the Solar and Lunar cosmic-ray shadows observed with Milagro. Milagro is a water-cerenkov detector for astrophysical TeV gamma and cosmic rays situated near Los Alamos NM. In the geomagnetic field, TeV cosmic rays are deflected on the order of a few degrees. The Moon acts a sink for cosmic rays so it is possible to observe a shadow of the Moon in the otherwise nearly isotropic arrival of cosmic rays. Such a shadow has been previously seen by several observatories. However, Milagro's unique capabilities allow measurement of the dependence of shadow's characteristics on cosmic-ray particle energy. This can provide the first energy calibration for an extensive air shower detector which is essentially independent of monte carlo simulations. The Sun is also a sink in the sky for cosmic rays and a Solar shadow has also been observed by several experiments. However, the Sun has it's own time varying magnetic field which is not completely known. Direct measurements have been made of this field on the Solar surface from the Zeeman effect and in areas of the far-field region through which satellites have passed. Milagro observation of the Solar shadow can be compared with simulations using theoretical models of the solar magnetic field to put constraints on the field in the near-Sun region.

  17. The Relation of Shadow Systems and ERP Systems—Insights from a Multiple-Case Study

    Directory of Open Access Journals (Sweden)

    Melanie Huber

    2016-01-01

    Full Text Available ERP systems integrate a major part of all business processes and organizations include them in their IT service management. Besides these formal systems, there are additional systems that are rather stand-alone and not included in the IT management tasks. These so-called ‘shadow systems’ also support business processes but hinder a high enterprise integration. Shadow systems appear during their explicit detection or during software maintenance projects such as enhancements or release changes of enterprise systems. Organizations then have to decide if and to what extent they integrate the identified shadow systems into their ERP systems. For this decision, organizations have to compare the capabilities of each identified shadow system with their ERP systems. Based on multiple-case studies, we provide a dependency approach to enable their comparison. We derive categories for different stages of the dependency and base insights into integration possibilities on these stages. Our results show that 64% of the shadow systems in our case studies are related to ERP systems. This means that they share parts or all of their data and/or functionality with the ERP system. Our research contributes to the field of integration as well as to the discussion about shadow systems.

  18. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Brorsen, Michael; Frigaard, Peter

    Denne rapport beskriver numeriske beregninger af forskellige flydergeometrier for bølgeenergianlæget Wave Star.......Denne rapport beskriver numeriske beregninger af forskellige flydergeometrier for bølgeenergianlæget Wave Star....

  19. Gravitational Waves

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Jonah Maxwell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-18

    This report has slides on Gravitational Waves; Pound and Rebka: A Shocking Fact; Light is a Ruler; Gravity is the Curvature of Spacetime; Gravitational Waves Made Simple; How a Gravitational Wave Affects Stuff Here; LIGO; This Detection: Neutron Stars; What the Gravitational Wave Looks Like; The Sound of Merging Neutron Stars; Neutron Star Mergers: More than GWs; The Radioactive Cloud; The Kilonova; and finally Summary, Multimessenger Astronomy.

  20. Wave Dragon

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Frigaard, Peter; Sørensen, H. C.

    1998-01-01

    This paper concerns with the development of the wave energy converter (WEC) Wave Dragon. This WEC is based on the overtopping principle. An overview of the performed research done concerning the Wave Dragon over the past years is given, and the results of one of the more comprehensive studies...

  1. Wave phenomena

    CERN Document Server

    Towne, Dudley H

    1988-01-01

    This excellent undergraduate-level text emphasizes optics and acoustics, covering inductive derivation of the equation for transverse waves on a string, acoustic plane waves, boundary-value problems, polarization, three-dimensional waves and more. With numerous problems (solutions for about half). ""The material is superbly chosen and brilliantly written"" - Physics Today. Problems. Appendices.

  2. Electromagnetic Waves

    DEFF Research Database (Denmark)

    This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis......, material characterization, electromagnetic properties of plasma, analysis and applications of periodic structures and waveguide components, etc....

  3. A cloud shadow detection method combined with cloud height iteration and spectral analysis for Landsat 8 OLI data

    Science.gov (United States)

    Sun, Lin; Liu, Xinyan; Yang, Yikun; Chen, TingTing; Wang, Quan; Zhou, Xueying

    2018-04-01

    Although enhanced over prior Landsat instruments, Landsat 8 OLI can obtain very high cloud detection precisions, but for the detection of cloud shadows, it still faces great challenges. Geometry-based cloud shadow detection methods are considered the most effective and are being improved constantly. The Function of Mask (Fmask) cloud shadow detection method is one of the most representative geometry-based methods that has been used for cloud shadow detection with Landsat 8 OLI. However, the Fmask method estimates cloud height employing fixed temperature rates, which are highly uncertain, and errors of large area cloud shadow detection can be caused by errors in estimations of cloud height. This article improves the geometry-based cloud shadow detection method for Landsat OLI from the following two aspects. (1) Cloud height no longer depends on the brightness temperature of the thermal infrared band but uses a possible dynamic range from 200 m to 12,000 m. In this case, cloud shadow is not a specific location but a possible range. Further analysis was carried out in the possible range based on the spectrum to determine cloud shadow location. This effectively avoids the cloud shadow leakage caused by the error in the height determination of a cloud. (2) Object-based and pixel spectral analyses are combined to detect cloud shadows, which can realize cloud shadow detection from two aspects of target scale and pixel scale. Based on the analysis of the spectral differences between the cloud shadow and typical ground objects, the best cloud shadow detection bands of Landsat 8 OLI were determined. The combined use of spectrum and shape can effectively improve the detection precision of cloud shadows produced by thin clouds. Several cloud shadow detection experiments were carried out, and the results were verified by the results of artificial recognition. The results of these experiments indicated that this method can identify cloud shadows in different regions with correct

  4. Mother-Blaming in the Shadow of Incest: Commentary on "Motherhood in the Shadow of Incest" by Rachel Lev-Wiesel

    Science.gov (United States)

    Faller, Kathleen Coulborn

    2007-01-01

    This commentary on "Motherhood in the Shadow of Incest" by Rachel Lev-Wiesel, is divided into three sections. In the first section, this author addresses the issue of the role of mothers in incest. Faller contends that, with regard to research findings on the role of mothers' own sexual victimization in her child's experience, previous research…

  5. Industrial Ecology and Environmental Lean Management: Lights and Shadows

    Directory of Open Access Journals (Sweden)

    Giuseppe Ioppolo

    2014-09-01

    Full Text Available Current industrial production is driven by increasing globalization, which has led to a steady increase in production volumes and complexity of products aimed at the pursuit of meeting the needs of customers. In this context, one of the main tools in the management of customer value is Lean Manufacturing or Production, though it is considered primarily as a set of tools to reduce the total cost of the resources needed to achieve such needs. This philosophy has recently been enriched in the literature with case studies that link Lean Management (LM with the improvement of environmental sustainability. The consequence is an expansion of the Computer Integrated Manufacturing (CIM; indeed, CIM, currently, combining and integrating the key business functions (e.g., business, engineering, manufacturing, and information management with a view of the life cycle, does not highlight the strategic role of the environmental aspects. In order to deal with the increasingly rapid environmental degradation that is reflected in society, in terms of both economy and quality of life, Industrial Ecology (IE introduced a new paradigm of principles and instruments of analysis and decision support (e.g., Life Cycle Assessment—LCA, Social Life Cycle Assessment -SLCA, Material Flow Account—MFA, etc. that can be considered as the main basis for integrating the environmental aspects in each strategy, design, production, final product, and end of life management, through the re-engineering of processes and activities towards the development of an eco-industrial system. This paper presents the preliminary observations based on a analysis of both theories (LM-IE and provides a possible assessment of the key factors relevant to their integration in a “lean environmental management”, highlighting both positives (lights and possible barriers (shadows.

  6. Investigating shadows: a pedagogical intervention project with primary school children

    Science.gov (United States)

    Noversa, Silvana; Abreu, Cátia; Varela, Paulo; Costa, Manuel F. M.

    2014-07-01

    This communication results from a pedagogical intervention project, carried out at a primary school in the district of Braga - Portugal. The intervention took place in a class of the 3rd year, composed of 16 students, and it incorporated the practice of inquiry-based science teaching addressing the theme "Light Experiments", which is part of the "Environmental Studies" curricular area. Various class activities were planned and implemented concerning some of the factors that influence the shadow of an object, in order to find answers to the following three questions: a) will 3rd year students, aged 7/8 years, be able to construct and execute an investigation strategy that involves manipulating and controlling variables? b) what are the main difficulties experienced by students in the designing and execution of such a strategy? c) how will students, in interaction with the teacher and with their peers, gradually design and execute their investigation strategy in order to respond to the problem formulated? The project adopted an action research methodology. A careful record was kept of the events most relevant to the questions under study in each class. This data was used to prepare the class diaries - descriptive and reflective narratives prepared based on recorded audio and field notes made during participant observation in the context of the classroom. A content analysis of the diaries has identified a few elements that provide answers to the research questions raised. In order to plan and implement a research project with children in the 7/8 years old range require a high level of scaffolding to allow students to gradually build a coherent strategy to tackle the research problem. Teacher's role is crucial. The teacher, by questioning and inducing reasoning and discussion, promotes encourages and regulates the cognitive activity of students. Some level of autonomy should be given to the students in large group collaborative work.

  7. Thermal inertias in the upper millimeters of the Martian surface derived using Phobos' shadow

    Science.gov (United States)

    Betts, Bruce H.; Murray, Bruce C.; Svitek, Tomas

    1995-01-01

    The first thermal images of Phobos' shadow on the surface of Mars, in addition to simultaneous visible images, were obtained by the Phobos'88 Termoskan instrument. The best observed shadow occurrence was on the flanks of Arsia Mons. For this occurrence, we combined the observed decrease in visible illumination of the surface with the observed decrease in brightness temperature to calculate thermal inertias of the Martian surface. The most realistic of our three models of eclipse cooling improves upon our preliminary model by including nonisothermal initial conditions and downward atmospheric flux. Most of our derived inertias fall within the range 38 to 59 J/(sq m s(exp 1/2) K), (0.9 to 1.4 x 10(exp -3) cal/(sq cm s(exp 1/2) K)) corresponding to dust-sized particles (for a homogeneous surface), consistent with previous theories of Tharsis as a current area of dust deposition. Viking infrared thermal mapper (IRTM) inertias are diurnally derived and are sensitive to centimeter depths, whereas the shadow-derived inertias sample the upper tenths of a millimeter of the surface. The shadow-derived inertias are lower than those derived from Viking IRTM measurements (84 to 147), however, uncertainties in both sets of derived inertias make conclusions about layering tenuous. Thus, near-surface millimeter versus centimeter layering may exist in this region, but if it does, it is likely not very significant. Both eclipse and diurnal inertias appear to increase near the eastern end of the shadow occurrence. We also analyzed a shadow occurrence near the crater Herschel that showed no observed cooling. This analysis was limited by cool morning temperatures and instrument sensitivity, but yielded a lower bound of 80 on eclipse inertias in that region. Based upon our results, we strongly recommend future spacecraft thermal observations of Phobos' shadow, and suggest that they will be most useful if they improve upon Terinoskan's geographic and temporal coverage and its accuracy.

  8. Thermal inertias in the upper millimeters of the Martian surace derived using Phobus' shadow

    Science.gov (United States)

    Betts, Bruce H.; Murray, Bruce C.; Svitek, Tomas

    1995-01-01

    The first thermal images of Phobos' shadow on the surface of Mars, in addition to simultaneous visible images, were obtained by the Phobus '88 Termoskan instrument. The best observed shadow occurence was on the flanks of Arsia Mons. For this occurence, we combined the observed decrease in visible illumination of the surface with the observed decrease in brightness temperature to calculate thermal inertias of the Martian surface. The most realistic of our three models of eclipse cooling improves upon our preliminary model by including nonisothermal initial conditions and downward atmospheric flux. Most of our derived inertias fall within the range 38 to 59 J/Sq m/S(exp 0.5)K (0.9 to 1.4 10(exp -3)Cal/Sq m/S(exp 0.5)/K), corresponding to dust-sized particles (for a homogeneous surface), consistent with previous theories of Tharsis as a currrent area of dust deposition. Viking infrared thermal mapper (IRTM) inertias are diurnally derived and are sensitive to centimeter depths, whereas the shadow-derived inertias sample the upper tenths of a millimeter of the surface. The shadow-derived inertias are lower than those derived from Viking IRTM measurements (84 to 147), however, uncertainties in both sets of derived inertias make conclusions about layering tenuous. Thus, near-surface millimeter versus centimeter layering may exist in this region, but if it does, it is likely not very significant. Both eclipse and diurnal inertias appear to increase near the eastern end of the shadow occurence. We also analyzed a shadow occurence near the crater Herschel that showed no observed cooling. This analysis was limited by cool morning temperatures and instrument sensitivity, but yielded a lower bound of 80 on eclipse inertias in that region. Based upon our results, we strongly recommend future spacecraft thermal observations of Phobus' shadow, and suggest that they will be most useful if they improve upon Termoskan's geographic and temporal coverage and its accuracy.

  9. Effects of frame shadow on the PV character of a photovoltaic/thermal system

    International Nuclear Information System (INIS)

    Wang, Yunyun; Pei, Gang; Zhang, Longcan

    2014-01-01

    Highlights: • We proposed a method for predicting the performance of a partly shaded PV cell. • Even a small shadow can significantly affect the performance of a PV/T system. • A parallel circuit is better than a series circuit in addressing partial shadows. • The total output of a series circuit within a day/year is higher than that of a parallel circuit. - Abstract: Most photovoltaic/thermal (PV/T) systems have an air layer between the glass cover and the cells to minimize heat loss and to improve overall efficiency. This feature is not found in typical PV systems. The frame border that supports the glass cover casts a shadow over the cells near the frame when sunlight is slanted. This design is common in PV/T systems. The objective of this study is to determine the effects of a frame shadow on PV/T systems. A mathematical model of a PV module in a PV/T system is established. An experimental research on a partly shaded single cell is then conducted. Based on the module model and the results of the experiment, a single cell model that simulates the performance of partly shaded cells is developed and integrated into an existing system model. The new model can be applied to simulate frame shadow in a PV/T system. Results show that the performance of a partly shaded single cell can be calculated as the cell operates below the average irradiation intensity of the shaded and unshaded parts. In the worst-case scenario, the frame shadow can cause a 39.3% decrease in photoelectric efficiency. Although the parallel circuit performs better than the series circuit in minimizing loss caused by the frame shadow, the latter has a higher total output

  10. Observation of three dimensional optical rogue waves through obstacles

    Energy Technology Data Exchange (ETDEWEB)

    Leonetti, Marco, E-mail: marco.leonetti@roma1.infn.it [Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Viale Regina Elena, 291 00161 Roma (RM) (Italy); Conti, Claudio [ISC-CNR and Department of Physics, University Sapienza, P.le Aldo Moro 5, I-00185 Roma (Italy)

    2015-06-22

    We observe three-dimensional rogue waves in the speckle distribution of a spatially modulated optical beam. Light is transmitted beyond a partially reflecting obstacle generating optical rogue waves at a controlled position in the shadow of the barrier. When the barrier transmits only 0.07% of the input laser power, we observe the mostly localized event. These results demonstrate that an optimum amount of spatial non-homogeneity maximizes the probability of a gigantic event while the technique we exploit enables to control light behind a fully reflective wall.

  11. Assimilation of Wave Imaging Radar Observations for Real-time Wave-by-Wave Forecasting

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Alexandra [Oregon State Univ., Corvallis, OR (United States); Haller, Merrick [Oregon State Univ., Corvallis, OR (United States). School of Civil & Construction Engineering; Walker, David [SRI International, Menlo Park, CA (United States); Lynett, Pat [Univ. of Southern California, Los Angeles, CA (United States)

    2017-08-29

    forecasting in real-time, as the GPU-based wave model backbone was very computationally efficient. The data assimilation algorithm was developed on a polar grid domain in order to match the sampling characteristics of the observation system (wave imaging marine radar). For verification purposes, a substantial set of synthetic wave data (i.e. forward runs of the wave model) were generated to be used as ground truth for comparison to the reconstructions and forecasts produced by Wavecast. For these synthetic cases, Wavecast demonstrated very good accuracy, for example, typical forecast correlation coefficients were between 0.84-0.95 when compared to the input data. Dependencies on shadowing, observational noise, and forecast horizon were also identified. During the second year of the project, a short field deployment was conducted in order to assess forecast accuracy under field conditions. For this, a radar was installed on a fishing vessel and observations were collected at the South Energy Test Site (SETS) off the coast of Newport, OR. At the SETS site, simultaneous in situ wave observations were also available owing to an ongoing field project funded separately. Unfortunately, the position and heading information that was available for the fishing vessel were not of sufficient accuracy in order to validate the forecast in a phase-resolving sense. Instead, a spectral comparison was made between the Wavecast forecast and the data from the in situ wave buoy. Although the wave and wind conditions during the field test were complex, the comparison showed a promising reconstruction of the wave spectral shape, where both peaks in the bimodal spectrum were represented. However, the total reconstructed spectral energy (across all directions and frequencies) was limited to 44% of the observed spectrum. Overall, wave-by-wave forecasting using a data assimilation approach based on wave imaging radar observations and a physics-based wave model shows promise for short-term phase

  12. Advanced dexterous manipulation for IED defeat : report on the feasibility of using the ShadowHand for remote operations.

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Robert J.

    2011-01-01

    Improvised Explosive Device (IED) defeat (IEDD) operations can involve intricate operations that exceed the current capabilities of the grippers on board current bombsquad robots. The Shadow Dexterous Hand from the Shadow Robot Company or 'ShadowHand' for short (www.shadowrobot.com) is the first commercially available robot hand that realistically replicates the motion, degrees-of-freedom and dimensions of a human hand (Figure 1). In this study we evaluate the potential for the ShadowHand to perform potential IED defeat tasks on a mobile platform.

  13. Policy measure for creating an integrated and brand-focused regional innovation system in tourism in a shadow destination:

    DEFF Research Database (Denmark)

    Brambini, Annalisa; Vang, Jan

    2013-01-01

    Tourism has often been hyped as an engine of regional growth and development but often failed to deliver the expected results. This is especially the case in shadow destinations. The concept of a shadow destination refers to a region whose relative attractioness is significantly lower than co......-located places. Based on regional innovation systems and place branding research the paper develops policy measures adapted to the specific challenges a shadow destination faces. Empirically, the appropriateness of the policy measures is demonstrated through applying it to a paradigmatic shadow destination...

  14. Analysis of shadowing effects on MIR photovoltaic and solar dynamic power systems

    Science.gov (United States)

    Fincannon, James

    1995-01-01

    The NASA Lewis Research Center is currently working with RSC-Energia, the Russian Space Agency, and Allied Signal in developing a flight demonstration solar dynamic power system. This type of power system is dependent upon solar flux that is reflected and concentrated into a thermal storage system to provide the thermal energy input to a closed-cycle Brayton heat engine. The solar dynamic unit will be flown on the Russian Mir space station in anticipation of use on the International Space Station Alpha. By the time the power system is launched, the Mir will be a spatially complex configuration which will have, in addition to the three-gimbaled solar dynamic unit, eleven solar array wings that are either fixed or track the Sun along one axis and a variety or repositionable habitation and experiment modules. The proximity of arrays to modules creates a situation which makes it highly probable that there will be varying solar flux due to shadowing on the solar dynamic unit and some of the arrays throughout the orbit. Shadowing causes fluctuations in the power output from the arrays and the solar dynamic power system, thus reducing the energy capabilities of the spacecraft. An assessment of the capabilities of the power system under these conditions is an important part in influencing the design and operations of the spacecraft and predicting its energy performance. This paper describes the results obtained from using the Orbiting Spacecraft Shadowing Analysis Station program that was integrated into the Station Power Analysis for Capability Evaluation (SPACE) electrical power system computer program. OSSA allows one to consider the numerous complex factors for analyzing the shadowing effects on the electrical power system including the variety of spacecraft hardware geometric configurations, yearly and daily orbital variations in the vehicle attitude and orbital maneuvers (for communications coverage, payload pointing requirements and rendezvous/docking with other

  15. Automated vessel shadow segmentation of fovea-centered spectral-domain images from multiple OCT devices

    Science.gov (United States)

    Wu, Jing; Gerendas, Bianca S.; Waldstein, Sebastian M.; Simader, Christian; Schmidt-Erfurth, Ursula

    2014-03-01

    Spectral-domain Optical Coherence Tomography (SD-OCT) is a non-invasive modality for acquiring high reso- lution, three-dimensional (3D) cross sectional volumetric images of the retina and the subretinal layers. SD-OCT also allows the detailed imaging of retinal pathology, aiding clinicians in the diagnosis of sight degrading diseases such as age-related macular degeneration (AMD) and glaucoma.1 Disease diagnosis, assessment, and treatment requires a patient to undergo multiple OCT scans, possibly using different scanning devices, to accurately and precisely gauge disease activity, progression and treatment success. However, the use of OCT imaging devices from different vendors, combined with patient movement may result in poor scan spatial correlation, potentially leading to incorrect patient diagnosis or treatment analysis. Image registration can be used to precisely compare disease states by registering differing 3D scans to one another. In order to align 3D scans from different time- points and vendors using registration, landmarks are required, the most obvious being the retinal vasculature. Presented here is a fully automated cross-vendor method to acquire retina vessel locations for OCT registration from fovea centred 3D SD-OCT scans based on vessel shadows. Noise filtered OCT scans are flattened based on vendor retinal layer segmentation, to extract the retinal pigment epithelium (RPE) layer of the retina. Voxel based layer profile analysis and k-means clustering is used to extract candidate vessel shadow regions from the RPE layer. In conjunction, the extracted RPE layers are combined to generate a projection image featuring all candidate vessel shadows. Image processing methods for vessel segmentation of the OCT constructed projection image are then applied to optimize the accuracy of OCT vessel shadow segmentation through the removal of false positive shadow regions such as those caused by exudates and cysts. Validation of segmented vessel shadows uses

  16. Cracking ShadowCrypt: Exploring the Limitations of Secure I/O Systems in Internet Browsers

    Directory of Open Access Journals (Sweden)

    Freyberger Michael

    2018-04-01

    Full Text Available An important line of privacy research is investigating the design of systems for secure input and output (I/O within Internet browsers. These systems would allow for users’ information to be encrypted and decrypted by the browser, and the specific web applications will only have access to the users’ information in encrypted form. The state-of-the-art approach for a secure I/O system within Internet browsers is a system called ShadowCrypt created by UC Berkeley researchers [23]. This paper will explore the limitations of ShadowCrypt in order to provide a foundation for the general principles that must be followed when designing a secure I/O system within Internet browsers. First, we developed a comprehensive UI attack that cannot be mitigated with popular UI defenses, and tested the efficacy of the attack through a user study administered on Amazon Mechanical Turk. Only 1 of the 59 participants who were under attack successfully noticed the UI attack, which validates the stealthiness of the attack. Second, we present multiple attack vectors against Shadow-Crypt that do not rely upon UI deception. These attack vectors expose the privacy weaknesses of Shadow DOM—the key browser primitive leveraged by ShadowCrypt. Finally, we present a sketch of potential countermeasures that can enable the design of future secure I/O systems within Internet browsers.

  17. FAST OCCLUSION AND SHADOW DETECTION FOR HIGH RESOLUTION REMOTE SENSING IMAGE COMBINED WITH LIDAR POINT CLOUD

    Directory of Open Access Journals (Sweden)

    X. Hu

    2012-08-01

    Full Text Available The orthophoto is an important component of GIS database and has been applied in many fields. But occlusion and shadow causes the loss of feature information which has a great effect on the quality of images. One of the critical steps in true orthophoto generation is the detection of occlusion and shadow. Nowadays LiDAR can obtain the digital surface model (DSM directly. Combined with this technology, image occlusion and shadow can be detected automatically. In this paper, the Z-Buffer is applied for occlusion detection. The shadow detection can be regarded as a same problem with occlusion detection considering the angle between the sun and the camera. However, the Z-Buffer algorithm is computationally expensive. And the volume of scanned data and remote sensing images is very large. Efficient algorithm is another challenge. Modern graphics processing unit (GPU is much more powerful than central processing unit (CPU. We introduce this technology to speed up the Z-Buffer algorithm and get 7 times increase in speed compared with CPU. The results of experiments demonstrate that Z-Buffer algorithm plays well in occlusion and shadow detection combined with high density of point cloud and GPU can speed up the computation significantly.

  18. The Shadow Economy of Czech Republic and Tax Evasion: The Currency Demand Approach

    Directory of Open Access Journals (Sweden)

    Dennis Nchor

    2016-01-01

    Full Text Available This study investigates the shadow economy of Czech Republic and the associated losses in tax revenue. The presence of a shadow economy may not necessarily be bad for the economies in which they prevail but they could cause huge losses to government revenue and could also constitute serious violation of labour regulations. The study uses the Currency Demand Approach. It measures the size of the shadow economy in two stages: a the econometric estimation of an aggregate money demand equation b the calculation of the value of the shadow economy through the quantity theory of money. The key variables in the study include: the total currency held outside the banking system, the number of automatic teller machines, the deposit interest rate, GDP deflator, the average tax, velocity of money, nominal GDP and nominal money supply. The results from the study show that the shadow economy of Czech Republic on the average is about 20.9 % as at the end of 2013 and the country loses an average tax revenue of about 7.2 % of GDP yearly. The data was obtained from the World Bank country indicators and the International Financial Statistics.

  19. Illumination robust face recognition using spatial adaptive shadow compensation based on face intensity prior

    Science.gov (United States)

    Hsieh, Cheng-Ta; Huang, Kae-Horng; Lee, Chang-Hsing; Han, Chin-Chuan; Fan, Kuo-Chin

    2017-12-01

    Robust face recognition under illumination variations is an important and challenging task in a face recognition system, particularly for face recognition in the wild. In this paper, a face image preprocessing approach, called spatial adaptive shadow compensation (SASC), is proposed to eliminate shadows in the face image due to different lighting directions. First, spatial adaptive histogram equalization (SAHE), which uses face intensity prior model, is proposed to enhance the contrast of each local face region without generating visible noises in smooth face areas. Adaptive shadow compensation (ASC), which performs shadow compensation in each local image block, is then used to produce a wellcompensated face image appropriate for face feature extraction and recognition. Finally, null-space linear discriminant analysis (NLDA) is employed to extract discriminant features from SASC compensated images. Experiments performed on the Yale B, Yale B extended, and CMU PIE face databases have shown that the proposed SASC always yields the best face recognition accuracy. That is, SASC is more robust to face recognition under illumination variations than other shadow compensation approaches.

  20. An Efficient and Robust Moving Shadow Removal Algorithm and Its Applications in ITS

    Directory of Open Access Journals (Sweden)

    Chin-Teng Lin

    2010-01-01

    Full Text Available We propose an efficient algorithm for removing shadows of moving vehicles caused by non-uniform distributions of light reflections in the daytime. This paper presents a brand-new and complete structure in feature combination as well as analysis for orientating and labeling moving shadows so as to extract the defined objects in foregrounds more easily in each snapshot of the original files of videos which are acquired in the real traffic situations. Moreover, we make use of Gaussian Mixture Model (GMM for background removal and detection of moving shadows in our tested images, and define two indices for characterizing non-shadowed regions where one indicates the characteristics of lines and the other index can be characterized by the information in gray scales of images which helps us to build a newly defined set of darkening ratios (modified darkening factors based on Gaussian models. To prove the effectiveness of our moving shadow algorithm, we carry it out with a practical application of traffic flow detection in ITS (Intelligent Transportation System—vehicle counting. Our algorithm shows the faster processing speed, 13.84 ms/frame, and can improve the accuracy rate in 4%∼10% for our three tested videos in the experimental results of vehicle counting.

  1. An Efficient and Robust Moving Shadow Removal Algorithm and Its Applications in ITS

    Directory of Open Access Journals (Sweden)

    Shou Yu-Wen

    2010-01-01

    Full Text Available We propose an efficient algorithm for removing shadows of moving vehicles caused by non-uniform distributions of light reflections in the daytime. This paper presents a brand-new and complete structure in feature combination as well as analysis for orientating and labeling moving shadows so as to extract the defined objects in foregrounds more easily in each snapshot of the original files of videos which are acquired in the real traffic situations. Moreover, we make use of Gaussian Mixture Model (GMM for background removal and detection of moving shadows in our tested images, and define two indices for characterizing non-shadowed regions where one indicates the characteristics of lines and the other index can be characterized by the information in gray scales of images which helps us to build a newly defined set of darkening ratios (modified darkening factors based on Gaussian models. To prove the effectiveness of our moving shadow algorithm, we carry it out with a practical application of traffic flow detection in ITS (Intelligent Transportation System—vehicle counting. Our algorithm shows the faster processing speed, 13.84 ms/frame, and can improve the accuracy rate in 4%~10% for our three tested videos in the experimental results of vehicle counting.

  2. Shadow analysis via the C+K Visioline: A technical note.

    Science.gov (United States)

    Houser, T; Zerweck, C; Grove, G; Wickett, R

    2017-11-01

    This research investigated the ability of shadow analysis (via the Courage + Khazaka Visioline and Image Pro Premiere 9.0 software) to accurately assess the differences in skin topography associated with photo aging. Analyses were performed on impressions collected from a microfinish comparator scale (GAR Electroforming) as well a series of impressions collected from the crow's feet region of 9 women who represent each point on the Zerweck Crow's Feet classification scale. Analyses were performed using a Courage + Khazaka Visioline VL 650 as well as Image Pro Premiere 9.0 software. Shadow analysis showed an ability to accurately measure the groove depth when measuring impressions collected from grooves of known depth. Several shadow analysis parameters showed a correlation with the expert grader ratings of crow's feet when averaging measurements taken from the North and South directions. The Max Depth parameter in particular showed a strong correlation with the expert grader's ratings which improved when a more sophisticated analysis was performed using Image Pro Premiere. When used properly, shadow analysis is effective at accurately measuring skin surface impressions for differences in skin topography. Shadow analysis is shown to accurately assess the differences across a range of crow's feet severity correlating to a 0-8 grader scale. The Visioline VL 650 is a good tool for this measurement, with room for improvement in analysis which can be achieved through third party image analysis software. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Comparison of Unsupervised Vegetation Classification Methods from Vhr Images after Shadows Removal by Innovative Algorithms

    Science.gov (United States)

    Movia, A.; Beinat, A.; Crosilla, F.

    2015-04-01

    The recognition of vegetation by the analysis of very high resolution (VHR) aerial images provides meaningful information about environmental features; nevertheless, VHR images frequently contain shadows that generate significant problems for the classification of the image components and for the extraction of the needed information. The aim of this research is to classify, from VHR aerial images, vegetation involved in the balance process of the environmental biochemical cycle, and to discriminate it with respect to urban and agricultural features. Three classification algorithms have been experimented in order to better recognize vegetation, and compared to NDVI index; unfortunately all these methods are conditioned by the presence of shadows on the images. Literature presents several algorithms to detect and remove shadows in the scene: most of them are based on the RGB to HSI transformations. In this work some of them have been implemented and compared with one based on RGB bands. Successively, in order to remove shadows and restore brightness on the images, some innovative algorithms, based on Procrustes theory, have been implemented and applied. Among these, we evaluate the capability of the so called "not-centered oblique Procrustes" and "anisotropic Procrustes" methods to efficiently restore brightness with respect to a linear correlation correction based on the Cholesky decomposition. Some experimental results obtained by different classification methods after shadows removal carried out with the innovative algorithms are presented and discussed.

  4. Enhancement of bone shadow region using local phase-based ultrasound transmission maps.

    Science.gov (United States)

    Hacihaliloglu, Ilker

    2017-06-01

    Ultrasound is increasingly being employed in different orthopedic procedures as an imaging modality for real-time guidance. Nevertheless, low signal-to-noise-ratio and different imaging artifacts continue to hamper the success of ultrasound-based procedures. Bone shadow region is an important feature indicating the presence of bone/tissue interface in the acquired ultrasound data. Enhancement and automatic detection of this region could improve the sensitivity of ultrasound for imaging bone and result in improved guidance for various orthopedic procedures. In this work, a method is introduced for the enhancement of bone shadow regions from B-mode ultrasound data. The method is based on the combination of three different image phase features: local phase tensor, local weighted mean phase angle, and local phase energy. The combined local phase image features are used as an input to an [Formula: see text] norm-based contextual regularization method which emphasizes uncertainty in the shadow regions. The enhanced bone shadow images are automatically segmented and compared against expert segmentation. Qualitative and quantitative validation was performed on 100 in vivo US scans obtained from five subjects by scanning femur and vertebrae bones. Validation against expert segmentation achieved a mean dice similarity coefficient of 0.88. The encouraging results obtained in this initial study suggest that the proposed method is promising enough for further evaluation. The calculated bone shadow maps could be incorporated into different ultrasound bone segmentation and registration approaches as an additional feature.

  5. Shadow corrosion testing in the INCA facility in the Studsvik R2 reactor

    International Nuclear Information System (INIS)

    Nystrand, A.C.; Lassing, A.

    1999-01-01

    Shadow corrosion is a phenomenon which occurs when zirconium alloys are in contact with or in proximity to other metallic objects in a boiling water reactor environment (BWR, RBMK, SGHWR etc.). An enhanced corrosion occurs on the zirconium alloy with the appearance of a 'shadow' of the metallic object. The magnitude of the shadow corrosion can be significant, and is potentially limiting for the lifetime of certain zirconium alloy components in BWRs and other reactors with a similar water chemistry. In order to evaluate the suitability of the In-Core Autoclave (INCA) in the Studsvik R2 materials testing reactor as an experimental facility for studying shadow corrosion, a demonstration test has been performed. A number of test specimens consisting of Zircaloy-2 tubing in contact with Inconel were exposed in an oxidising water chemistry. Some of the specimens were placed within the reactor core and some above the core. The conclusion of this experiment after post irradiation examination is that it is possible to use the INCA facility in the Studsvik R2 reactor to develop a significant level of shadow corrosion after only 800 hours of irradiation. (author)

  6. Tree Wave Migration Across an Elevation Gradient in the Altai Mountains, Siberia

    Science.gov (United States)

    Kharuk, Viacheslav I.; Im, Sergei T.; Dvinskaya, Maria L.; Ranson, Kenneth J.; Petrov, Il'ya

    2017-01-01

    The phenomenon of tree waves (hedges and ribbons) formation within the alpine ecotone in Altai Mountains and its response to observed air temperature increase was considered. At the upper limit of tree growth Siberian pine (Pinus sibirica) forms hedges on windward slopes and ribbons on the leeward ones. Hedges were formed by prevailing winds and oriented along winds direction. Ribbons were formed by snow blowing and accumulating on the leeward slope and perpendicular to the prevailing winds, as well as to the elevation gradient. Hedges were always linked with microtopography features, whereas ribbons were not. Trees are migrating upward by waves and new ribbons and hedges are forming at or near tree line, whereas at lower elevations ribbons and hedges are being transformed into closed forests. 19 Time series of high-resolution satellite scenes (from 1968 to 2010) indicated an upslope shift in the position ribbons averaged 15526 m (or 3.7 m yr -1) and crown closure increased (about 3590). The hedges advance was limited by poor regeneration establishment and was negligible. Regeneration within the ribbon zone was approximately 2.5 times (5060 vs 2120 ha -1) higher then within the hedges zone. During the last four decades, Siberian pine in both hedges and ribbons strongly increased its growth increment and recent tree growth rate for 50 year old trees was about twice higher than recorded for similarly aged trees at the beginning of the 20th century. Hedges and ribbons are phenomena that are widespread within the southern and northern Siberian Mountains

  7. The betrayal of democracy: Tiananmen's shadow over Japan

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    2008-12-01

    Full Text Available La heroica lucha del pueblo chino por la libertad política en 1989 estimuló a la Europa del Este y a la URSS a abandonar su sistema de partido único. La Guerra Fría terminó abruptamente bajo el acicate del incidente de la Plaza Tiananmen. Este artículo explora el otro lado oscuro del incidente de Tiananmen en el escenario internacional: su profunda sombra sobre Japón. En base a la experiencia personal del autor, el artículo revisa y analiza el fracaso de Japón en su transformación política en la región durante este período histórico desde dos aspectos: 1 ¿Por qué y cómo el gobierno japonés tuvo que seguir a China económicamente? 2 ¿Por qué y cómo el gobierno japonés traicionó la democracia y los derechos humanos? El artículo concluye que las relaciones Chino-japonesas deberían basarse en los  principios de derechos humanos y democracia._________________ABSTRACT:The Chinese people's heroic struggle for political freedom in 1989 encouraged East Europe and the USSR to abandon their single-party system. The Cold War ended abruptly under the stimulus of the Tiananmen Square Incident. This article explores the other dark side of the Tiananmen Incident in the international stage: its deep shadow over Japan. Based on the author's personal experience, the article records, reviews and analyzes Japan's failure in its political transformation in the region during this historical period from two aspects: 1 Why and how the Japanese government had to engage China economically?; 2 Why and how the Japanese government betrayed democracy and human rights regarding China? The article concludes that Sino-Japanese relations should be based on principles of human rights and democracy.

  8. The effects of segmentation-based shadow removal on across-date settlement type classification of panchromatic QuickBird images

    CSIR Research Space (South Africa)

    Luus, FPS

    2013-06-01

    Full Text Available ) d2-shadow (e) FS : d1 (f) d1-shadow (g) FS : d2 (h) d2-shadow (i) OIS : d1 (j) d1-shadow (k) OIS : d2 (l) d2-shadow Fig. 7. Supervised shadow detection examples (shown in orange) paired with original images for the three main settlement classes FSB... [FSB] Formal Settlements [FS] Ordered Informal Settlements [OIS] Non-Builtup [NBU] Fig. 14. A second image of the study area, acquired on 18 October 2005, with a thematic classification using training data from another date. 0 0.1 0.2 0.3 0.4 0.572 74...

  9. Gravitation Waves

    CERN Multimedia

    CERN. Geneva

    2005-01-01

    We will present a brief introduction to the physics of gravitational waves and their properties. We will review potential astrophysical sources of gravitational waves, and the physics and astrophysics that can be learned from their study. We will survey the techniques and technologies for detecting gravitational waves for the first time, including bar detectors and broadband interferometers, and give a brief status report on the international search effort, with special emphasis on the LIGO detectors and search results.

  10. Shape and position of the shadow in the {delta} = 2 Tomimatsu-Sato spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Bambi, Cosimo; Yoshida, Naoki, E-mail: cosimo.bambi@ipmu.j, E-mail: naoki.yoshida@ipmu.j [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8583 (Japan)

    2010-10-21

    Within 5-10 years, very long baseline interferometry facilities will be able to observe the 'shadow' of super-massive black hole candidates. This will allow us, for the first time, to test gravity in the strong field regime. In this paper, we numerically study the photon orbits in the {delta} = 2 Tomimatsu-Sato spacetime. The {delta} = 2 Tomimatsu-Sato spacetime is a stationary, axisymmetric and asymptotically flat exact solution of the vacuum Einstein equations. We compare the associated shadow with the one of Kerr black holes. The shape of the shadow in the {delta} = 2 Tomimatsu-Sato spacetime is oblate and the difference between the two axes can be as high as 6% when viewed on the equatorial plane. We argue that future space sub-mm interferometers (e.g. VSOP-3) may distinguish the two cases, and thus are able to test the cosmic censorship conjecture.

  11. Shadowing on Apollo 12 Solar Cells and Possible Movement of the ALSEP Central Station

    Science.gov (United States)

    Berman, Paul A.; Williams, David R.

    2014-01-01

    A fortuitous arrangement of a west-facing solar cell and a bracket on the Apollo 12 ALSEP (Apollo Lunar Surface Experiments Package) has allowed us to precisely determine the relative position of the Sun near sunset relative to the Apollo 12 central station over a period of nearly 8 years. The small bracket, mounted on the central station due west of the cell, casts a shadow on the cell near sunset, decreasing the output of the cell proportional to the area of shadow covering the cell. The pattern of shadowing by the bracket gives good agreement with the known change of solar azimuth on a yearly timescale, but the pattern gradually but constantly changed from year-to-year, in a manner inconsistent with the known and changing position of the Sun.

  12. Pixels grouping and shadow cache for faster integral 3D ray tracing

    Science.gov (United States)

    Youssef, Osama; Aggoun, Amar; Wolf, Wayne H.; McCormick, Malcolm

    2002-05-01

    This paper presents for the first time, a theory for obtaining the optimum pixel grouping for improving the coherence and the shadow cache in integral 3D ray-tracing in order to reduce execution time. A theoretical study of the number of shadow cache hits with respect to the properties of the lenses and the shadow size and its location is discussed with analysis for three different styles of pixel grouping in order to obtain the optimum grouping. The first style traces rows of pixels in the horizontal direction, the second traces similar pixels in adjacent lenses in the horizontal direction, and the third traces columns of pixels in the vertical direction. The optimum grouping is a combination of all three dependant up on the number of cache hits in each. Experimental results show validation of the theory and tests on benchmark scenes show that up to a 37% improvement in execution time can be achieved by proper pixel grouping.

  13. Elegant Shadow Making Tiny Force Visible for Water-Walking Arthropods and Updated Archimedes' Principle.

    Science.gov (United States)

    Zheng, Yelong; Lu, Hongyu; Yin, Wei; Tao, Dashuai; Shi, Lichun; Tian, Yu

    2016-10-07

    Forces acted on legs of water-walking arthropods with weights in dynes are of great interest for entomologist, physicists, and engineers. While their floating mechanism has been recognized, the in vivo leg forces stationary have not yet been simultaneously achieved. In this study, their elegant bright-edged leg shadows are used to make the tiny forces visible and measurable based on the updated Archimedes' principle. The force was approximately proportional to the shadow area with a resolution from nanonewton to piconewton/pixel. The sum of leg forces agreed well with the body weight measured with an accurate electronic balance, which verified updated Archimedes' principle at the arthropod level. The slight changes of vertical body weight focus position and the body pitch angle have also been revealed for the first time. The visualization of tiny force by shadow is cost-effective and very sensitive and could be used in many other applications.

  14. Heliostat blocking and shadowing efficiency in the video-game era

    International Nuclear Information System (INIS)

    Ramos, Alberto

    2014-02-01

    Blocking and shadowing is one of the key effects in designing and evaluating a thermal central receiver solar tower plant. Therefore it is convenient to develop efficient algorithms to compute the area of an heliostat blocked or shadowed by the rest of the field. In this paper we explore the possibility of using very efficient clipping algorithms developed for the video game and imaging industry to compute the blocking and shadowing efficiency of a solar thermal plant layout. We propose an algorithm valid for arbitrary position, orientation and size of the heliostats. This algorithm turns out to be very accurate, free of assumptions and fast. We show the feasibility of the use of this algorithm to the optimization of a solar plant by studying a couple of examples in detail.

  15. Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun

    Science.gov (United States)

    Amenomori, M.; Bi, X. J.; Chen, D.; Chen, T. L.; Chen, W. Y.; Cui, S. W.; Danzengluobu, Ding, L. K.; Feng, C. F.; Feng, Zhaoyang; Feng, Z. Y.; Gou, Q. B.; Guo, Y. Q.; He, H. H.; He, Z. T.; Hibino, K.; Hotta, N.; Hu, Haibing; Hu, H. B.; Huang, J.; Jia, H. Y.; Jiang, L.; Kajino, F.; Kasahara, K.; Katayose, Y.; Kato, C.; Kawata, K.; Kozai, M.; Labaciren, Le, G. M.; Li, A. F.; Li, H. J.; Li, W. J.; Liu, C.; Liu, J. S.; Liu, M. Y.; Lu, H.; Meng, X. R.; Miyazaki, T.; Mizutani, K.; Munakata, K.; Nakajima, T.; Nakamura, Y.; Nanjo, H.; Nishizawa, M.; Niwa, T.; Ohnishi, M.; Ohta, I.; Ozawa, S.; Qian, X. L.; Qu, X. B.; Saito, T.; Saito, T. Y.; Sakata, M.; Sako, T. K.; Shao, J.; Shibata, M.; Shiomi, A.; Shirai, T.; Sugimoto, H.; Takita, M.; Tan, Y. H.; Tateyama, N.; Torii, S.; Tsuchiya, H.; Udo, S.; Wang, H.; Wu, H. R.; Xue, L.; Yamamoto, Y.; Yamauchi, K.; Yang, Z.; Yuan, A. F.; Yuda, T.; Zhai, L. M.; Zhang, H. M.; Zhang, J. L.; Zhang, X. Y.; Zhang, Y.; Zhang, Yi; Zhang, Ying; Zhaxisangzhu, Zhou, X. X.; Tibet AS γ Collaboration

    2018-01-01

    We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disk center in the "away" ("toward") interplanetary magnetic field (IMF) sector. By comparing with numerical simulations based on the solar magnetic field model, we find that the average IMF strength in the away (toward) sector is 1.54 ±0.21stat±0.20syst (1.62 ±0.15stat±0.22syst ) times larger than the model prediction. These demonstrate that the observed Sun's shadow is a useful tool for the quantitative evaluation of the average solar magnetic field.

  16. ``The sun is sleeping now'': Early learning about light and shadows

    Science.gov (United States)

    Segal, Gilda; Cosgrove, Mark

    1993-12-01

    To keep intuitive knowledge fluid for an extended time, we wish to encourage young children to examine continuously those intuitive explanations for natural phenomena which later become hard wired, highly resistant to development or change. To assist this we designed a learning package which integrated three extensively researched educational strategies (cooperative learning, informal inquiry and familiar context) for children to explore their notions about the topic light. Children in a kindergarten class were encouraged to share their ideas about shadows and shadow formation with peers, as they took part in explorations of shadow formation inside and outside their classroom. Whole class discussions, small group conversations and final conversations between researcher and small groups provide insights into social and individual construction of knowledge, young children's abilities to be scientific and the social construction of gender.

  17. Heliostat blocking and shadowing efficiency in the video-game era

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Alberto [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Ramos, Francisco [Nevada Software Informatica S.L., Madrid (Spain)

    2014-02-15

    Blocking and shadowing is one of the key effects in designing and evaluating a thermal central receiver solar tower plant. Therefore it is convenient to develop efficient algorithms to compute the area of an heliostat blocked or shadowed by the rest of the field. In this paper we explore the possibility of using very efficient clipping algorithms developed for the video game and imaging industry to compute the blocking and shadowing efficiency of a solar thermal plant layout. We propose an algorithm valid for arbitrary position, orientation and size of the heliostats. This algorithm turns out to be very accurate, free of assumptions and fast. We show the feasibility of the use of this algorithm to the optimization of a solar plant by studying a couple of examples in detail.

  18. Method and apparatus for shadow aperture backscatter radiography (SABR) system and protocol

    Science.gov (United States)

    Shedlock, Daniel (Inventor); Jacobs, Alan M. (Inventor); Jacobs, Sharon Auerback (Inventor); Dugan, Edward (Inventor)

    2010-01-01

    A shadow aperture backscatter radiography (SABR) system includes at least one penetrating radiation source for providing a penetrating radiation field, and at least one partially transmissive radiation detector, wherein the partially transmissive radiation detector is interposed between an object region to be interrogated and the radiation source. The partially transmissive radiation detector transmits a portion of the illumination radiation field. A shadow aperture having a plurality of radiation attenuating regions having apertures therebetween is disposed between the radiation source and the detector. The apertures provide illumination regions for the illumination radiation field to reach the object region, wherein backscattered radiation from the object is detected and generates an image by the detector in regions of the detector that are shadowed by the radiation attenuation regions.

  19. Knowledge Management without Management -- Shadow IT in Knowledge-intensive Manufacturing Practices

    DEFF Research Database (Denmark)

    Steinhueser, Melanie; Waizenegger, Lena; Vodanovich, Shahper

    2017-01-01

    study contributes to knowledge management research by showing how private IT use can change existing knowledge management practices. At the same time, we are able to give rich insights into the rise of Shadow IT in a manufacturing context which takes place in a selforganised way without knowledge......The voluntary use of private device by employees without formal approval of the IT department, commonly termed Shadow IT, is an increasingly widespread phenomenon. In this paper, we study the role of private smartphones (and related applications like WhatsApp) in knowledge-intensive practices...... of the management. This enables us to take a step towards a knowledge management strategy perspective on Shadow IT....

  20. A uniform geometrical optics and an extended uniform geometrical theory of diffraction for evaluating high frequency EM fields near smooth caustics and composite shadow boundaries

    Science.gov (United States)

    Constantinides, E. D.; Marhefka, R. J.

    1994-01-01

    A uniform geometrical optics (UGO) and an extended uniform geometrical theory of diffraction (EUTD) are developed for evaluating high frequency electromagnetic (EM) fields within transition regions associated with a two and three dimensional smooth caustic of reflected rays and a composite shadow boundary formed by the caustic termination or the confluence of the caustic with the reflection shadow boundary (RSB). The UGO is a uniform version of the classic geometrical optics (GO). It retains the simple ray optical expressions of classic GO and employs a new set of uniform reflection coefficients. The UGO also includes a uniform version of the complex GO ray field that exists on the dark side of the smooth caustic. The EUTD is an extension of the classic uniform geometrical theory of diffraction (UTD) and accounts for the non-ray optical behavior of the UGO reflected field near caustics by using a two-variable transition function in the expressions for the edge diffraction coefficients. It also uniformly recovers the classic UTD behavior of the edge diffracted field outside the composite shadow boundary transition region. The approach employed for constructing the UGO/EUTD solution is based on a spatial domain physical optics (PO) radiation integral representation for the fields which is then reduced using uniform asymptotic procedures. The UGO/EUTD analysis is also employed to investigate the far-zone RCS problem of plane wave scattering from two and three dimensional polynomial defined surfaces, and uniform reflection, zero-curvature, and edge diffraction coefficients are derived. Numerical results for the scattering and diffraction from cubic and fourth order polynomial strips are also shown and the UGO/EUTD solution is validated by comparison to an independent moment method (MM) solution. The UGO/EUTD solution is also compared with the classic GO/UTD solution. The failure of the classic techniques near caustics and composite shadow boundaries is clearly

  1. Design, fabrication and commissioning of motorized scanning bed mechanism for shadow shield whole body counting system

    International Nuclear Information System (INIS)

    Arun, B.; Varalakshimi, S.; Manohari, M.; Mathiyarasu, R.

    2012-01-01

    A new scanning bed mechanism for shadow shield counting system is designed, fabricated and commissioned at RSD, IGCAR. The present motorized scanning bed mechanism has varying scan speeds, state of art limit sensors, smooth bed movement, touch screen based software controlled operation parameters with UPS power back-up. In view of the improved personnel safety the entire system has been designed to operate with low voltage power supply (24V). The evaluation demonstrated that the incorporation of the new motorized scanning mechanism has not affected the counting performance of the shadow shield wholebody counting system. (author)

  2. The Effect of Topographic Shadowing by Ice on Irradiance in the Greenland Ice Sheet Ablation Zone

    Science.gov (United States)

    Leidman, S. Z.; Rennermalm, A. K.; Ryan, J.; Cooper, M. G.; Smith, L. C.

    2017-12-01

    Accurately predicting runoff contributions to global sea level rise requires more refined surface mass balance (SMB) models of the Greenland Ice Sheet (GrIS). Topographic shadowing has shown to be important in the SMB of snow-covered regions, yet SMB models for the GrIS generally ignore how surface topography affects spatial variability of incoming solar radiation on a surface. In the ablation zone of Southwest Greenland, deeply incised supraglacial drainage features, fracturing, and large-scale bed deformation result in extensive areas of rough surface topography. This topography blocks direct radiation such that shadowed areas receive less energy for melting while other topographic features such as peaks recieve more energy. In this study, we quantify how shadowing from local topography features changes incoming solar radiation. We apply the ArcGIS Pro Solar Radiation Toolset to calculate the direct and diffuse irradiance in sunlit and shadowed areas by determining the sun's movement for every half hour increment of 2016. Multiple digital elevation models (DEMs) with spatial resolutions ranging from 0.06 to 5m were derived from fixed wing and quadcopter UAV imagery collected in summer 2016 and the ArcticDEM dataset. Our findings show that shadowing significantly decreases irradiance compared to smoothed surfaces where local topography is removed. This decrease is exponentially proportional to the DEM pixel sized with 5m DEMs only able to capture a small percentage of the effect. Applying these calculations to the ArcticDEM to cover a larger study area indicates that decreases in irradiance are nonlinearly proportional to elevation with highly crevassed areas showing a larger effect from shadowing. Even so, shading at higher elevations reduces irradiance enough to result in several centimeters snow water equivalence (SWE) per year of over-prediction of runoff in SMB models. Furthermore, analysis of solar radiation products shows that shadowing predicts albedo

  3. Model of alpha particle diffusion in the outer limiter shadow of TFTR

    International Nuclear Information System (INIS)

    Wang, S.; Academia Sinica, Hefei, Anhui; Zweben, S.J.

    1996-05-01

    A new code, Monte Carlo Collisional Stochastic Orbit Retracing (MCCSOR), has been developed to model the alpha particle loss signal as measured by the outer midplane scintillator detector in TFTR. The shadowing effects due to the outer limiters and the detector itself have been included, along with a pitch angle scattering and stochastic ripple diffusion. Shadowing by the outer limiters has a strong effect on both the magnitude and pitch angle distribution of the calculated loss. There is at least qualitative agreement between the calculated results and the experimental data

  4. Energy Level Performance of Packet Delivery Schemes in Wireless Sensor Networks in Shadowed Channel

    Directory of Open Access Journals (Sweden)

    Arnab NANDI

    2010-07-01

    Full Text Available This paper evaluates energy level performance of three packet delivery schemes in a Wireless Sensor Networks (WSN in shadowed channel. Three different information delivery mechanisms are investigated using regenerative relays with or without error correction capability. Energy consumption for successful delivery of a data packet for each mechanism is evaluated and compared under several conditions of node density, bit rate, transmit power etc. Energy efficiency of different retransmission schemes is evaluated. Further an optimal packet length based on energy efficiency is derived. Impact of different level of severity of shadowing on energy consumption is also investigated. Further impact of fixed and optimal packet size on energy consumption is analyzed.

  5. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Brorsen, Michael; Frigaard, Peter

    Nærværende rapport beskriver numeriske beregninger af den hydrodynamiske interaktion mellem 5 flydere i bølgeenergianlægget Wave Star.......Nærværende rapport beskriver numeriske beregninger af den hydrodynamiske interaktion mellem 5 flydere i bølgeenergianlægget Wave Star....

  6. Coupled orbit-attitude motion of high area-to-mass ratio (HAMR) objects including efficient self-shadowing

    Science.gov (United States)

    Früh, Carolin; Jah, Moriba K.

    2014-02-01

    This paper shows the effect of self-shadowing on the coupled attitude-orbit dynamics of objects with high area-to-mass ratios (HAMR) in simulating standard multi layer insulation materials (MLI) as tilted single rigid sheets. Efficient and computationally fast self-shadowing methods have been developed. This includes an approximate self-shadowing method and a rapid exact self-shadowing method. Accuracy considerations are made and the effect of a chosen tessellation is shown. The coupled orbit-attitude perturbations of solar radiation pressure and Earth gravity field are taken into account. The results are compared to the attitude-orbit dynamics, when neglecting self-shadowing effects. An averaged physical shadow-map model is developed and compared to the full self-shadowing simulation. The combined effect of solar radiation pressure and self-shadowing leads to a rapid spin-up of the objects, even though they have uniform reflection properties. As a result, the observed brightness of these objects is subject to rapid changes.

  7. Spreading of thin-film metal patterns deposited on nonplanar surfaces using a shadow mask micromachined in si (110)

    NARCIS (Netherlands)

    Tiggelaar, Roald M.; Berenschot, Johan W.; Elwenspoek, Michael Curt; Gardeniers, Johannes G.E.; Dorsman, R.; Kleijn, C.R.

    The application of a three dimensional, self-aligning shadow mask in (110)-oriented silicon for thin-film metal deposition is discussed. This shadow mask is used for the deposition of metal tracks on the bottom of structures with vertical sidewalls, i.e., the patterning of metal catalytic patches

  8. Creating cloud-free Landsat ETM+ data sets in tropical landscapes: cloud and cloud-shadow removal

    Science.gov (United States)

    Sebastián Martinuzzi; William A. Gould; Olga M. Ramos Gonzalez

    2007-01-01

    Clouds and cloud shadows are common features of visible and infrared remotelysensed images collected from many parts of the world, particularly in humid and tropical regions. We have developed a simple and semiautomated method to mask clouds and shadows in Landsat ETM+ imagery, and have developed a recent cloud-free composite of multitemporal images for Puerto Rico and...

  9. Shadow-Reading: Guidelines for a Socially-Mediated Approach to Reading in the Second/Foreign Language Classroom

    Science.gov (United States)

    Commander, Millie; de Guerrero, María C. M.

    2016-01-01

    This paper describes shadow-reading, a pedagogical technique aimed at fostering reading comprehension and retention in second (L2) or foreign language (FL) classrooms. The technique is an adaptation of "conversational shadowing," a procedure which requires listeners to repeat what their interlocutors say in an attempt to remember the…

  10. Theory and empiricism of shadow economy - an economic analysis example for Austria

    International Nuclear Information System (INIS)

    Kuntzer, H.-P.

    2000-09-01

    Illegally circulating streams of net output will exist as long as economic events are registered and taxed by state authorities. Since the beginning of the eighties this part of the economic process has been more and more involved in scientific and political discussions not least because of the stagnating officially registered domestic content (as a result of two oil crisis) which lead to a continually financial crisis of all social security systems in Europe. Even if the shadow economic domestic content of GDP in Austria can be seen as relatively low in comparison to international figures, the steady increase of this sector during the last few years gives rise to concerns. In order to approach the phenomenon of shadow economy and especially illegal activities in the Alpine republic this treatise gives an abstract on the state of affairs as far as theoretical researches on the shadow economy is concerned. In this connection the following influencing factors are seen as important. On the one hand the variety of costs that go with the factor work (direct and indirect taxes, social security contributions and regulating costs) and on the other hand the steadily rising offers of illegal activities as a result of decreasing working hours and increasing unemployment. Moreover this development is supported by the growing sullenness towards state authorities (hypotheses of changing values). The interplay of all these factors ends up in an increasing share value of shadow economic activities in the OECD. The effects of this circumstance are evaluated ambivalently by theory because there are negative effects (growing unemployment, low tax receipts) as well as positive effects (induced costs, better supply of consumer demands). Punitive measures to control these activities are also regarded as ineffective. In order to approach the shadow economy - especially in Austria - this treatise first deals with the different methods to measure shadow economic activities, which are all

  11. Orientation with a Viking sun-compass, a shadow-stick, and two calcite sunstones under various weather conditions.

    Science.gov (United States)

    Bernáth, Balázs; Blahó, Miklós; Egri, Adám; Barta, András; Kriska, György; Horváth, Gábor

    2013-09-01

    It is widely accepted that Vikings used sun-compasses to derive true directions from the cast shadow of a gnomon. It has been hypothesized that when a cast shadow was not formed, Viking navigators relied on crude skylight polarimetry with the aid of dichroic or birefringent crystals, called "sunstones." We demonstrate here that a simple tool, that we call "shadow-stick," could have allowed orientation by a sun-compass with satisfying accuracy when shadows were not formed, but the sun position could have reliably been estimated. In field tests, we performed orientation trials with a set composed of a sun-compass, two calcite sunstones, and a shadow-stick. We show here that such a set could have been an effective orientation tool for Vikings only when clear, blue patches of the sky were visible.

  12. Black hole shadow in an asymptotically flat, stationary, and axisymmetric spacetime: The Kerr-Newman and rotating regular black holes

    Science.gov (United States)

    Tsukamoto, Naoki

    2018-03-01

    The shadow of a black hole can be one of the strong observational evidences for stationary black holes. If we see shadows at the center of galaxies, we would say whether the observed compact objects are black holes. In this paper, we consider a formula for the contour of a shadow in an asymptotically-flat, stationary, and axisymmetric black hole spacetime. We show that the formula is useful for obtaining the contour of the shadow of several black holes such as the Kerr-Newman black hole and rotating regular black holes. Using the formula, we can obtain new examples of the contour of the shadow of rotating black holes if assumptions are satisfied.

  13. In vitro study of relationship between bile duct stone and posterior acoustic shadow using human liver phantom

    International Nuclear Information System (INIS)

    Cho, S.W.; KIm, M.J.; Yu, H. S.; Lee, C. T.; Park, C. Y.

    1983-01-01

    The ultrasonic diagnosis of bile duct stone is still difficult and disappointing, especially compared with the diagnostic accuracy of gall stone. We analyzed ultrasonic findings of the relationship between bile duct stone and posterior acoustic shadow under different conditions in vitro real time scans of bile duct stones using human liver tissue phantom. The results were as follows: 1. In vitro real time scans of each 1 to 6mm sized 23 stones, even the detection of the 1mm sized stones were possible in 3 cases among 5 cases when using 5MHz transducer, however there shows no definite posterior acoustic shadow in all cases of 1mm sized stones when using 2.4 MHz probe. 2. The posterior acoustic shadows were demonstrated in almost all the stones more than 2mm size except two stones, each 2mm and 4mm stones, among 13 stones, and the reflected echoes from the stones and posterior acoustic shadows were more evident when using higher frequency probe. 3. In real time scans of 4 to 6 mm sized 3 stones using 3.5MHz probe at different depth, only faint posterior acoustic shadows were noted when the stones were placed deeper than the focal range of the probe, while dense posterior acoustic shadows were identified when the stones were placed within the focal range of the probe. 4. When 7 to 9 mm sized stones were scanned in different tubes, posterior acoustic shadows were not dense in thick rubber tuber as in condom or thin rubber tube. After pulling of thick rubber tube for the purpose of reducing fluid-stone interface, previous posterior acoustic shadows were no more identified. 5 When the 1 to 3 mm sized multiple stones were evenly distributed in rubber tube, multiple dense acoustic shadows were demonstrated, while there shows no definite posterior acoustic shadows after impaction of these stones by inclining the phantom box

  14. Wave Dragon

    DEFF Research Database (Denmark)

    Tedd, James; Kofoed, Jens Peter; Knapp, W.

    2006-01-01

    power of the device. The project development team has gained much soft experience from working in the harsh offshore environment. In particular the effect of marine growth in the draft tubes of the turbines has been investigated. The control of the device has been a focus for development as is operates......Wave Dragon is a floating wave energy converter working by extracting energy principally by means of overtopping of waves into a reservoir. A 1:4.5 scale prototype has been sea tested for 20 months. This paper presents results from testing, experiences gained and developments made during...

  15. Surface Water-Ice Deposits in the Northern Shadowed Regions of Ceres

    Science.gov (United States)

    Platz, T.; Nathues, A.; Schorghofer, N.; Preusker, F.; Mazarico, E.; Schroeder, S. E.; Byrne, S.; Kneissl, T.; Schmedemann, N.; Combe, J.-P.; hide

    2016-01-01

    Ceres, a dwarf planet located in the main asteroid belt, has a low bulk density, and models predict that a substantial amount of water ice is present in its mantle and outer shell. The Herschel telescope and the Dawn spacecraft have observed the release of water vapor from Ceres, and exposed water ice has been detected by Dawn on its surface at mid-latitudes. Water molecules from endogenic and exogenic sources can also be cold-trapped in permanent shadows at high latitudes, as happens on the Moon and Mercury. Here we present the first image-based survey of Ceres's northern permanent shadows and report the discovery of bright deposits in cold traps. We identify a minimum of 634 permanently shadowed craters. Bright deposits are detected on the floors of just 10 of these craters in multiscattered light. We spectroscopically identify one of the bright deposits as water ice. This detection strengthens the evidence that permanently shadowed areas have preserved water ice on airless planetary bodies.

  16. Plant Leaf Imaging using Time of Flight Camera under Sunlight, Shadow and Room Conditions

    DEFF Research Database (Denmark)

    Kazmi, Wajahat; Foix, Sergi; Alenya, Guillem

    2012-01-01

    In this article, we analyze the effects of ambient light on Time of Flight (ToF) depth imaging for a plant's leaf in sunlight, shadow and room conditions. ToF imaging is sensitive to ambient light and we try to find the best possible integration times (IT) for each condition. This is important...

  17. Shadow poles in coupled-channel problems calculated with the Berggren basis

    Science.gov (United States)

    Id Betan, R. M.; Kruppa, A. T.; Vertse, T.

    2018-02-01

    Background: In coupled-channels models the poles of the scattering S matrix are located on different Riemann sheets. Physical observables are affected mainly by poles closest to the physical region but sometimes shadow poles have considerable effect too. Purpose: The purpose of this paper is to show that in coupled-channels problems all poles of the S matrix can be located by an expansion in terms of a properly constructed complex-energy basis. Method: The Berggren basis is used for expanding the coupled-channels solutions. Results: The locations of the poles of the S matrix for the Cox potential, constructed for coupled-channels problems, were numerically calculated and compared with the exact ones. In a nuclear physics application the Jπ=3 /2+ resonant poles of 5He were calculated in a phenomenological two-channel model. The properties of both the normal and shadow resonances agree with previous findings. Conclusions: We have shown that, with an appropriately chosen Berggren basis, all poles of the S matrix including the shadow poles can be determined. We have found that the shadow pole of 5He migrates between Riemann sheets if the coupling strength is varied.

  18. Tax reform in Georgia and the size of the shadow economy

    Czech Academy of Sciences Publication Activity Database

    Torosyan, K.; Filer, Randall K.

    2014-01-01

    Roč. 22, č. 1 (2014), s. 179-210 ISSN 0967-0750 Institutional support: PRVOUK-P23 Keywords : hidden/shadow economy * tax reform * consumer behaviour Subject RIV: AH - Economics Impact factor: 0.423, year: 2014

  19. The Longitudinal Elderly Person Shadowing Program: Outcomes from an Interprofessional Senior Partner Mentoring Program

    Science.gov (United States)

    Basran, Jenny F. S.; Dal Bello-Haas, Vanina; Walker, Doreen; MacLeod, Peggy; Allen, Bev; D'Eon, Marcel; McKague, Meredith; Chopin, Nicola S.; Trinder, Krista

    2012-01-01

    The University of Saskatchewan's Longitudinal Elderly Person Shadowing (LEPS) is an interprofessional senior mentors program (SMP) where teams of undergraduate students in their first year of medicine, pharmacy, and physiotherapy; 2nd year of nutrition; 3rd year nursing; and 4th year social work partner with community-dwelling older adults.…

  20. Degree counting and Shadow system for Toda system of rank two: One bubbling

    Science.gov (United States)

    Lee, Youngae; Lin, Chang-Shou; Wei, Juncheng; Yang, Wen

    2018-04-01

    We initiate the program for computing the Leray-Schauder topological degree for Toda systems of rank two. This program still contains a lot of challenging problems for analysts. As the first step, we prove that if a sequence of solutions (u1k ,u2k) blows up, then one of hje ujk/∫Mhje ujk dvg, j = 1 , 2 tends to a sum of Dirac measures. This is so-called the phenomena of weak concentration. Our purposes in this article are (i) to introduce the shadow system due to the bubbling phenomena when one of parameters ρi crosses 4π and ρj ∉ 4 πN where 1 ≤ i ≠ j ≤ 2; (ii) to show how to calculate the topological degree of Toda systems by computing the topological degree of the general shadow systems; (iii) to calculate the topological degree of the shadow system for one point blow up. We believe that the degree counting formula for the shadow system would be useful in other problems.

  1. Shadow netWorkspace: An Open Source Intranet for Learning Communities

    Science.gov (United States)

    Laffey, James M.; Musser, Dale

    2006-01-01

    Shadow netWorkspace (SNS) is a web application system that allows a school or any type of community to establish an intranet with network workspaces for all members and groups. The goal of SNS has been to make it easy for schools and other educational organizations to provide network services in support of implementing a learning community. SNS is…

  2. State Estimation and Forecasting of the Ski-Slope Model Using an Improved Shadowing Filter

    Science.gov (United States)

    Mat Daud, Auni Aslah

    In this paper, we present the application of the gradient descent of indeterminism (GDI) shadowing filter to a chaotic system, that is the ski-slope model. The paper focuses on the quality of the estimated states and their usability for forecasting. One main problem is that the existing GDI shadowing filter fails to provide stability to the convergence of the root mean square error and the last point error of the ski-slope model. Furthermore, there are unexpected cases in which the better state estimates give worse forecasts than the worse state estimates. We investigate these unexpected cases in particular and show how the presence of the humps contributes to them. However, the results show that the GDI shadowing filter can successfully be applied to the ski-slope model with only slight modification, that is, by introducing the adaptive step-size to ensure the convergence of indeterminism. We investigate its advantages over fixed step-size and how it can improve the performance of our shadowing filter.

  3. Influence of shadow effect on the strength of steel beams exposed to fire

    DEFF Research Database (Denmark)

    Virdi, Kuldeep; Wickström, Ulf

    2013-01-01

    in or in direct contact with concrete are not considered appropriately - only the reduction of the exposed area is taken into account. In addition, the shadow effect is rarely considered in structures with both concrete and asteel elements such as composite floors. It has been mainly used for stand-alone columns...

  4. MEASURING THE EFFECTS OF THE "TIMING OF TIME" ON SHADOW VALUES OF LEISURE TIME

    OpenAIRE

    Larson, Douglas M.; Lew, Daniel K.; Barrett, James M.

    2002-01-01

    The "timing of leisure time" is important to determining its opportunity cost. Shadow values of different leisure activities from a model of consumer choice subject to multiple binding time constraints are estimated from survey data on peoples' preferences for different activities, their time and money costs, and their consumption choices.

  5. Editorial: Shadows of the past, visions of the future in African ...

    African Journals Online (AJOL)

    Editorial: Shadows of the past, visions of the future in African literatures and cultures. R West-Pavlov. Abstract. No abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/tvl.v51i2.1 · AJOL African Journals Online. HOW TO USE ...

  6. Interprofessional education through shadowing experiences in multi-disciplinary clinical settings

    Directory of Open Access Journals (Sweden)

    Moore Ainsley E

    2010-12-01

    Full Text Available Abstract The World Health Organization has recently added Interprofessional Education (IPE to its global health agenda recognizing it as a necessary component of all health professionals' education. We suggest mandatory interprofessional shadowing experiences as a mechanism to be used by chiropractic institutions to address this agenda. IPE initiatives of other professions (pharmacy and medicine are described along with chiropractic. This relative comparison of professions local to our jurisdiction in Ontario, Canada is made so that the chiropractic profession may take note that they are behind other health care providers in implementing IPE. Interprofessional shadowing experiences would likely take place in a multi-disciplinary clinical setting. We offer an example of how two separate professions within a Family Health Team (FHT can work together in such a setting to enhance both student learning and patient care. For adult learners, using interprofessional shadowing experiences with learner-derived and active objectives across diverse health professional groups may help to improve the educational experience. Mandatory interprofessional shadowing experiences for chiropractors during their training can enhance future collaborative practice and provide success in reaching a goal common to each profession - improved patient care.

  7. Direct solar wind proton access into permanently shadowed lunar polar craters

    Science.gov (United States)

    Zimmerman, M. I.; Farrell, W. M.; Stubbs, T. J.; Halekas, J. S.

    2011-12-01

    Recent analyses of Lunar Prospector neutron spectrometer (LPNS) data have suggested that high abundances of hydrogen exist within cold traps at the lunar poles, and it has often been assumed that hydrogen-bearing volatiles sequestered in permanent shadow are topographically shielded from sputtering by solar wind protons. However, recent simulation results are presented showing that textbf{solar wind protons clearly access the floor of an idealized, shadowed lunar crater} through a combination of thermal and ambipolar processes, in effect creating a plasma "mini-wake". These simulations are the first to model the mini-wake environment in two spatial dimensions with a self-consistent lunar surface-plasma interaction. Progress is reported on constraining the nonzero particle fluxes and energies incident on kilometer-scale shadowed topography, such as a small crater embedded within a larger one. The importance of direct solar wind proton bombardment is discussed within the context of understanding the stability and inventory of hydrogen-bearing volatiles in shadow at the lunar poles. textit{The support of the National Lunar Science Institute, the DREAM Institute, LPROPS, and the NASA Postdoctoral Program at NASA Goddard Space Flight Center administered by ORAU are gratefully acknowledged.}

  8. MPPT-Based Control Algorithm for PV System Using iteration-PSO under Irregular shadow Conditions

    Directory of Open Access Journals (Sweden)

    M. Abdulkadir

    2017-02-01

    Full Text Available The conventional maximum power point tracking (MPPT techniques can hardly track the global maximum power point (GMPP because the power-voltage characteristics of photovoltaic (PV exhibit multiple local peaks in irregular shadow, and therefore easily fall into the local maximum power point. These conditions make it very challenging, and to tackle this deficiency, an efficient Iteration Particle Swarm Optimization (IPSO has been developed to improve the quality of solution and convergence speed of the traditional PSO, so that it can effectively track the GMPP under irregular shadow conditions. This proposed technique has such advantages as simple structure, fast response and strong robustness, and convenient implementation. It is applied to MPPT control of PV system in irregular shadow to solve the problem of multi-peak optimization in partial shadow. In order to verify the rationality of the proposed algorithm, however, recently the dynamic MPPT performance under varying irradiance conditions has been given utmost attention to the PV society. As the European standard EN 50530 which defines the recommended varying irradiance profiles, was released lately, the corresponding researchers have been required to improve the dynamic MPPT performance. This paper tried to evaluate the dynamic MPPT performance using EN 50530 standard. The simulation results show that iterative-PSO method can fast track the global MPP, increase tracking speed and higher dynamic MPPT efficiency under EN 50530 than the conventional PSO.

  9. Inspecting Shadows of Past Classroom Practices: A Search for Students' Voices

    Science.gov (United States)

    Sullivan, Patricia

    2012-01-01

    Our pedagogical histories lean on textbooks, institutional records, and the words of famous teachers. Students rarely appear in situ. Here, the voices of two very different Progressive Era students cast spotlights on the shadows of long-ago classroom practices--offering a liveliness that is difficult to recover, but worth seeking. (Contains 5…

  10. Shadow Replication: An Energy-Aware, Fault-Tolerant Computational Model for Green Cloud Computing

    Directory of Open Access Journals (Sweden)

    Xiaolong Cui

    2014-08-01

    Full Text Available As the demand for cloud computing continues to increase, cloud service providers face the daunting challenge to meet the negotiated SLA agreement, in terms of reliability and timely performance, while achieving cost-effectiveness. This challenge is increasingly compounded by the increasing likelihood of failure in large-scale clouds and the rising impact of energy consumption and CO2 emission on the environment. This paper proposes Shadow Replication, a novel fault-tolerance model for cloud computing, which seamlessly addresses failure at scale, while minimizing energy consumption and reducing its impact on the environment. The basic tenet of the model is to associate a suite of shadow processes to execute concurrently with the main process, but initially at a much reduced execution speed, to overcome failures as they occur. Two computationally-feasible schemes are proposed to achieve Shadow Replication. A performance evaluation framework is developed to analyze these schemes and compare their performance to traditional replication-based fault tolerance methods, focusing on the inherent tradeoff between fault tolerance, the specified SLA and profit maximization. The results show that Shadow Replication leads to significant energy reduction, and is better suited for compute-intensive execution models, where up to 30% more profit increase can be achieved due to reduced energy consumption.

  11. Direct Solar Wind Proton Access into Permanently Shadowed Lunar Polar Craters

    Science.gov (United States)

    Zimmerman, M. I.; Farrell, W. M.; Stubbs, T. J.; Halekas, J. S.

    2011-01-01

    Recent analyses of Lunar Prospector neutron spectrometer (LPNS) data have suggested that high abundances of hydrogen exist within cold traps at the lunar poles, and it has often been assumed that hydrogen-bearing volatiles sequestered in permanent shadow are topographically shielded from sputtering by solar wind protons. However, recent simulation results are presented showing that solar wind protons clearly access the floor of an idealized, shadowed lunar crater through a combination of thermal and ambipolar processes, in effect creating a plasma "miniwake". These simulations are the first to model the mini-wake environment in two spatial dimensions with a self-consistent lunar surface-plasma interaction. Progress is reported on constraining the nonzero particle fluxes and energies incident on kilometer-scale shadowed topography, such as a small crater embedded within a larger one. The importance of direct solar wind proton bombardment is discussed within the context of understanding the stability and inventory of hydrogen-bearing volatiles in shadow at the lunar poles. The support of the National Lunar Science institute, the DREAM institute, LPROPS, and the NASA Postdoctoral Program at NASA Goddard Space Flight Center administered by ORAU are gratefully acknowledged.

  12. Shadow Scholars and the Rise of the Dissertation Service Industry: Can We Maintain Academic Integrity?

    Science.gov (United States)

    White, Jeffry L.

    2016-01-01

    Notable interest was generated when Dave Tomar's book, "The Shadow Scholar: How I Made a Living Helping College Kids Cheat," was first published. While ghostwriters and paper mills have long been part of the academic landscape, a far more ominous enterprise has appeared that targets master's and doctoral students seeking assistance with…

  13. History of Science and Conceptual Change: The Formation of Shadows by Extended Light Sources

    Science.gov (United States)

    Dedes, Christos; Ravanis, Konstantinos

    2009-01-01

    This study investigates the effectiveness of a teaching conflict procedure whose purpose was the transformation of the representations of 12-16-year-old pupils in Greece concerning light emission and shadow formation by extended light sources. The changes observed during the children's effort to destabilize and reorganise their representations…

  14. Shadow effect on photovoltaic potentiality analysis using 3D city models

    NARCIS (Netherlands)

    Alam, N.; Coors, V.; Zlatanova, S.; Van Oosterom, P.J.M.

    2012-01-01

    Due to global warming, green-house effect and various other drawbacks of existing energy sources, renewable energy like Photovoltaic system is being popular for energy production. The result of photovoltaic potentiality analysis depends on data quality and parameters. Shadow rapidly decreases

  15. Does body shadow improve the efficacy of virtual reality-based training with BTS NIRVANA?

    Science.gov (United States)

    Russo, Margherita; De Luca, Rosaria; Naro, Antonino; Sciarrone, Francesca; Aragona, Bianca; Silvestri, Giuseppe; Manuli, Alfredo; Bramanti, Alessia; Casella, Carmela; Bramanti, Placido; Calabrò, Rocco Salvatore

    2017-01-01

    Abstract Background: Aim of the present study was to evaluate whether the presence of body shadows during virtual reality (VR) training with BTS NIRVANA (BTs-N) may lead to a better functional recovery. Methods: We enrolled 20 poststroke rehabilitation inpatients, who underwent a neurocognitive-rehabilitative training consisting of 24 sessions (3 times a week for 8 weeks) of BTs-N. All the patients were randomized into 2 groups: semi-immersive virtual training with (S-IVTS group) or without (S-IVT group) body shadows. Each participant was evaluated before (T0) and immediately (T1) after the end of the training (Trial Registration Number: NCT03095560). Results: The S-IVTS group showed a greater improvement in visuo-constructive skills and sustained attention, as compared with the S-IVT group. The other measures showed nonsignificant within-group and between-group differences. Conclusion: Our results showed that body shadow may represent a high-priority class of stimuli that act by “pushing” attention toward the body itself. Further studies are needed to clarify the role of body shadow in promoting the internal representation construction and thus self-recognition. PMID:28930852

  16. Social capital as a determinant of the shadow economy in the Republic of Serbia

    Directory of Open Access Journals (Sweden)

    Natasa Golubovic

    2015-08-01

    Full Text Available The design and implementation of the measures aimed at incorporating informal economic activities into the existing formal regulatory framework assume the knowledge of the causes and structure of the informal activity. The influence of the institutional factors that encourage the development of the shadow economy (the tax burden, the degree of the regulation of the economy, the capacity of the state administration were the subject of extensive theoretical and empirical research. In contrast, the impact of social capital, i.e. the characteristics of social ties and relations, on the shadow economy has been investigated to a much lesser extent. Starting from the fact that the informal sector of the Serbian economy is so widespread that it represents a serious obstacle to the business activities of Serbian enterprises, the aim of this study is to investigate whether the characteristics of social ties and relations, or social capital in the Republic of Serbia (RS, represent a fertile ground for the growth of the shadow economy. In this context, the characteristics and frequency of social contacts, particularized trust and institutional trust will be separately analyzed as the determinants of the shadow economy in RS.

  17. Evaluation of Tower Shadowing on Anemometer Measurements at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Bruggeman, David Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-14

    The objective of this study is to evaluate the effect of tower shadowing from the meteorology towers at LANL during 2014. This study is in response to the Department of Energy Meteorological Coordinating Council visit in 2015 that recommended an evaluation of any biases in the wind data introduced by the tower and boom alignment at all meteorology towers.

  18. Review: The Shadow of the Hummingbird | Krüger | Tydskrif vir ...

    African Journals Online (AJOL)

    Author: Athol Fugard. Book Title: The Shadow of the Hummingbird. Cape Town: Human & Rousseau, 2015. 96 pp. ISBN: 978-0-7981-6993-6. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/tvl.v53i1.30 · AJOL African Journals ...

  19. Hybridity in Willa Cather's "Death Comes for the Archbishop" and "Shadows on the Rock"

    Science.gov (United States)

    Fard, Maryam Heydari; Pirnajmuddin, Hossein

    2015-01-01

    Willa Cather wrote "Death Comes for the Archbishop" and "Shadows on the Rock" based on the missionary life of Europeans in Quebec and New Mexico. In both novels she depicts a different type of colonizer-colonized relationship. The colonizers arrive with their stereotypical views about the natives to purportedly civilize them.…

  20. Reflections and unprompted observations by healthcare students of an interprofessional shadowing visit.

    Science.gov (United States)

    Wright, Anna; Hawkes, Gillian; Baker, Becky; Lindqvist, Susanne Marie

    2012-07-01

    This paper reports work from a Centre for Interprofessional Practice in a higher education institution in the UK that offers four levels of interprofessional learning (IPL) to all healthcare students. The second level (IPL2) integrates professional practice into the learning process, requiring students to shadow a qualified healthcare professional (from a different profession) for half a day. Students complete a reflective statement upon their learning experience on their return. A study was undertaken to analyse students' reflective statements in depth to see their observations and reflections on the shadowing visit. Using frame analysis, 160 reflective statements were analyzed, identifying common words and phrases used by students, which were then grouped together under six themes. Three of these related directly to the assignment: communication styles and techniques; communication between healthcare professionals and comparison of students' own and other healthcare professionals' roles. Three themes emerged from student's own interpretation of observations and reflections made during the shadowing of a different professional: attitudes toward other professions; power structures between professionals and patients and between professionals and impact of communication on patient care. Interprofessional shadowing gives students an opportunity to observe communication between healthcare professionals and patients and to reflect on broader issues surrounding collaborative working.

  1. All sonic anemometers need to correct for transducer and structural shadowing in their velocity measurements

    Science.gov (United States)

    John M. Frank; William J. Massman; Edward Swiatek; Herb A. Zimmerman; Brent E. Ewers

    2016-01-01

    Sonic anemometry is fundamental to all eddy-covariance studies of surface energy and ecosystem carbon and water balance. Recent studies have shown that some nonorthogonal anemometers underestimate vertical wind. Here it is hypothesized that this is due to a lack of transducer and structural shadowing correction. This is tested with a replicated intercomparison...

  2. Flow visualization analysis of two-phase flow through contraction using shadow-image and PIV

    International Nuclear Information System (INIS)

    Watanabe, Satoshi; Morimoto, Yuichiro; Ishikawa, Masaaki; Okamoto, Koji; Madarame, Haruki

    2004-01-01

    Gas-liquid two-phase flow through contraction was visualized and analyzed using shadow-image and PIV. The flow channel has reducer, where the width was contracted from 50mm to 20mm. Bubble deformation and concurrent velocity fluctuation was investigated varying superficial liquid flow rate from 0.4m/s to 8.0m/s. (author)

  3. Outage Probability of MRC for κ-μ Shadowed Fading Channels under Co-Channel Interference.

    Science.gov (United States)

    Chen, Changfang; Shu, Minglei; Wang, Yinglong; Yang, Ming; Zhang, Chongqing

    2016-01-01

    In this paper, exact closed-form expressions are derived for the outage probability (OP) of the maximal ratio combining (MRC) scheme in the κ-μ shadowed fading channels, in which both the independent and correlated shadowing components are considered. The scenario assumes the received desired signals are corrupted by the independent Rayleigh-faded co-channel interference (CCI) and background white Gaussian noise. To this end, first, the probability density function (PDF) of the κ-μ shadowed fading distribution is obtained in the form of a power series. Then the incomplete generalized moment-generating function (IG-MGF) of the received signal-to-interference-plus-noise ratio (SINR) is derived in the closed form. By using the IG-MGF results, closed-form expressions for the OP of MRC scheme are obtained over the κ-μ shadowed fading channels. Simulation results are included to validate the correctness of the analytical derivations. These new statistical results can be applied to the modeling and analysis of several wireless communication systems, such as body centric communications.

  4. Limitations of patterning thin films by shadow mask high vacuum chemical vapor deposition

    International Nuclear Information System (INIS)

    Reinke, Michael; Kuzminykh, Yury; Hoffmann, Patrik

    2014-01-01

    A key factor in engineering integrated devices such as electro-optic switches or waveguides is the patterning of high quality crystalline thin films into specific geometries. In this contribution high vacuum chemical vapor deposition (HV-CVD) was employed to grow titanium dioxide (TiO 2 ) patterns onto silicon. The directed nature of precursor transport – which originates from the high vacuum environment during the process – allows shading certain regions on the substrate by shadow masks and thus depositing patterned thin films. While the use of such masks is an emerging field in stencil or shadow mask lithography, their use for structuring thin films within HV-CVD has not been reported so far. The advantage of the employed technique is the precise control of lateral spacing and of the distance between shading mask and substrate surface which is achieved by manufacturing them directly on the substrate. As precursor transport takes place in the molecular flow regime, the precursor impinging rates (and therefore the film growth rates) on the surface can be simulated as function of the reactor and shading mask geometry using a comparatively simple mathematical model. In the current contribution such a mathematical model, which predicts impinging rates on plain or shadow mask structured substrates, is presented. Its validity is confirmed by TiO 2 -deposition on plain silicon substrates (450 °C) using titanium tetra isopropoxide as precursor. Limitations of the patterning process are investigated by the deposition of TiO 2 on structured substrates and subsequent shadow mask lift-off. The geometry of the deposits is according to the mathematical model. Shading effects due to the growing film enables to fabricate deposits with predetermined variations in topography and non-flat top deposits which are complicated to obtain by classical clean room processes. As a result of the enhanced residual pressure of decomposition products and titanium precursors and the

  5. Investigation of Wave Energy Converter Effects on the Nearshore Environment: A Month-Long Study in Monterey Bay CA.

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Jesse D.; Chang, Grace; Magalen, Jason; Jones, Craig

    2014-09-01

    A modified version of an indust ry standard wave modeling tool, SNL - SWAN, was used to perform model simulations for hourly initial wave conditio ns measured during the month of October 2009. The model was run with an array of 50 wave energy converters (WECs) and compared with model runs without WECs. Maximum changes in H s were found in the lee of the WEC array along the angles of incident wave dire ction and minimal changes were found along the western side of the model domain due to wave shadowing by land. The largest wave height reductions occurred during observed typhoon conditions and resulted in 14% decreases in H s along the Santa Cruz shoreline . Shoreline reductions in H s were 5% during s outh swell wave conditions and negligible during average monthly wave conditions.

  6. Heat Waves

    Science.gov (United States)

    ... quickly. - Drink plenty of water regularly and often. - Eat small meals and eat more often. - Avoid using salt tablets ... plenty of water during a heat wave and eat smaller, more frequent meals. Text from "Are You Prepared?" by the Cass ( ...

  7. Efficient Wave Energy Amplification with Wave Reflectors

    DEFF Research Database (Denmark)

    Kramer, Morten Mejlhede; Frigaard, Peter Bak

    2002-01-01

    Wave Energy Converters (WEC's) extract wave energy from a limited area, often a single point or line even though the wave energy is generally spread out along the wave crest. By the use of wave reflectors (reflecting walls) the wave energy is effectively focused and increased to approximately 130...... for different geometries of the wave reflectors and optimal geometrical design parameters are specified. On this basis inventors of WEC's can evaluate whether a specific WEC possible could benefit from wave reflectors....

  8. Shadows and Silence: Analysis of Social and Environmental Reports of the Energy Sector

    Directory of Open Access Journals (Sweden)

    Fabrício do Nascimento Moreira

    2016-04-01

    Full Text Available While it is acknowledged that there has been a rapid growth in the disclosure of social and environmental responsibility reports of companies, it is assumed also that there is a long way to go in that these reports meet their users, stakeholders, considering the characteristics of materiality, consistency, integrity and accountability in the construction of accounting information. So with the need to advance this discussion, some scholars in the field of environmental accounting began to suggest, among other ideas, building models formed by basic reporting accounts silence and shadow, they could identify differences between perceived environmental performance the public interested in the activities and affairs of the entity and performance that corporations claim they have achieved through their accounts and reports publicly available. While the report is constructed from silent speech, vision and corporate positioning, the second shadow report, part of the stakeholder perspective, i.e., the desires of stakeholders in the activities and business of the company. The objective of the study is to explore if the preparation of shadow and silent report can contribute to the improvement of the information quality of corporate environmental performance reports. To achieve this goal, it was prepared the silent and shadow reports of ELETROBRAS system and later confronted. It was found that companies have trouble to expose negative social and environmental impacts in reports; the volume of news published on corporate websites is not as significant as shown by other studies and the companies, over the years, didn’t publish the reports in a regular basis and with the same pattern; among other findings. Finally, it was concluded that the shadow and silent reports could be used to improve the information quality in corporate environmental performance reports.

  9. Active Ageing and Shadow Economy in Romania. An Empirical Causality Analysis

    Directory of Open Access Journals (Sweden)

    Adriana AnaMaria DAVIDESCU

    2015-06-01

    Full Text Available The paper aims to analyze the unidirectional relationship from active ageing phenomena to the size of the Romanian shadow economy in order to see if the unofficial sector represents a social buffer for older workers who have lower labor market opportunities. In order to do that, we applied two important causality analyses, Granger and Toda-Yamamoto, based on quarterly data over the period 2000-2010. The size of the Romanian shadow economy was previously estimated using a revised version of the currency demand approach based on autoregressive distributed lag (ARDL approach. For active ageing, the employment rate for older workers was used as proxy. The cointegration empirical results highlight the existence of a positive long-run relationship between employment rate of elderly and unofficial sector. The empirical causality results conclude that there is a unidirectional Granger causality that runs from employment rate of older workers to shadow economy both on long-run and short-run. The empirical results of Toda-Yamamoto revealed the absence of a short-run causal relationship from employment rate for older workers to the size of shadow economy. One possible explanation for the existence of a positive relationship that runs from employment rate of elderly to unofficial sector can be the low capacity of the economy to generate proper jobs, so this age group of older workers does not have qualifications that meet the needs of formal economy, and therefore shadow economy becomes an alternative to formal work and it may provide a buffer for some workers who have few alternative labor market opportunities. Another alternative could be the fact that this age group of elderly remains occupied in the formal lab our market, but with low earnings and they work in informal activities in order to supplement their income.

  10. The stress shadow induced by the 1975-1984 Krafla rifting episode

    KAUST Repository

    Maccaferri, F.

    2013-03-01

    It has been posited that the 1975–1984 Krafla rifting episode in northern Iceland was responsible for a significant drop in the rate of earthquakes along the Húsavík-Flatey Fault (HFF), a transform fault that had previously been the source of several magnitude 6–7 earthquakes. This compelling case of the existence of a stress shadow has never been studied in detail, and the implications of such a stress shadow remain an open question. According to rate-state models, intense stress shadows cause tens of years of low seismicity rate followed by a faster recovery phase of rate increase. Here, we compare the long-term predictions from a Coulomb stress model of the rifting episode with seismological observations from the SIL catalog (1995–2011) in northern Iceland. In the analyzed time frame, we find that the rift-induced stress shadow coincides with the eastern half of the fault where the observed seismicity rates are found to be significantly lower than expected, given the historical earthquake activity there. We also find that the seismicity rates on the central part of the HFF increased significantly in the last 17 years, with the seismicity progressively recovering from west to east. Our observations confirm that rate-state theory successfully describes the long-term seismic rate variation during the reloading phase of a fault invested by a negative Coulomb stress. Coincident with this recovery, we find that the b-value of the frequency-magnitude distribution changed significantly over time. We conclude that the rift-induced stress shadow not only decreased the seismic rate on the eastern part of the HFF but also temporarily modified how the system releases seismic energy, with more large magnitude events in proportion to small ones. This behavior is currently being overturned, as rift-induced locking is now being compensated by tectonic forcing.

  11. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter

    Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Byggeri og Anlæg med bølgeenergianlæget Wave Star.......Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Byggeri og Anlæg med bølgeenergianlæget Wave Star....

  12. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Andersen, Thomas Lykke

    Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star.......Nærværende rapport beskriver modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star....

  13. Blast Waves

    CERN Document Server

    Needham, Charles E

    2010-01-01

    The primary purpose of this text is to document many of the lessons that have been learned during the author’s more than forty years in the field of blast and shock. The writing therefore takes on an historical perspective, in some sense, because it follows the author’s experience. The book deals with blast waves propagating in fluids or materials that can be treated as fluids. It begins by distinguishing between blast waves and the more general category of shock waves. It then examines several ways of generating blast waves, considering the propagation of blast waves in one, two and three dimensions as well as through the real atmosphere. One section treats the propagation of shocks in layered gases in a more detailed manner. The book also details the interaction of shock waves with structures in particular reflections, progressing from simple to complex geometries, including planar structures, two-dimensional structures such as ramps or wedges, reflections from heights of burst, and three-dimensional st...

  14. Mountain wave motions determined by the Esrange MST radar

    Directory of Open Access Journals (Sweden)

    A. Réchou

    1999-07-01

    Full Text Available A European campaign of ground-based radar, lidar and optical measurements was carried out during the winter of 1996/1997 (28 December-2 February to study lee waves in the northern part of Scandinavia. The participants operated ozone lidars, backscatter lidars and MST radars at ALOMAR/Andoya and Esrange/Kiruna, and an ALIS imaging system in Kiruna. The Andoya site was generally windward of the Scandinavian mountains, the Kiruna site on the leeward side. The goal of the experiment was to examine the influence of lee waves on the formation of Polar Stratospheric Clouds (PSCs. This paper studies the radar data from MST-radar ESRAD located at Esrange [68.°N, 21.°E], i.e. in the lee of the mountains. We present three cases where strong lee waves were observed: in one case they propagated upwards to the lower stratosphere and in the other two cases they were trapped or absorbed in the troposphere. We examine the local waves and the direction and strength of the local wind using the radar, the synoptic meteorological situation using weather maps (European Meteorological Bulletin and the synoptic stratospheric temperatures using ECMWF data. We observed that waves propagate up to the stratosphere during frontal passages. When anticyclonic ridges are present, the propagation to the stratosphere is very weak. This is due to trapping of the waves at or below the tropopause. We also show that the radar data alone can be used to characterise the different weather conditions for the three cases studied (through the variation of the height of the tropopause. The synoptic stratospheric temperatures in the three cases were similar, and were above the expected threshold for PSC formation. Lidar and visual observation of PSCs and nacreous clouds, respectively, showed that these were present only in the case when the lee waves propagated up to the lower stratosphere.Key words. Atmospheric composition and structure (aerosols and particles · Electromagnetic (wave

  15. Interstitial shadow on chest CT is associated with the onset of interstitial lung disease caused by chemotherapeutic drugs

    International Nuclear Information System (INIS)

    Niho, Seiji; Goto, Koichi; Yoh, Kiyotaka; Kim, Y.H.; Ohmatsu, Hironobu; Kubota, Kaoru; Saijo, Nagahiro; Nishiwaki, Yutaka

    2006-01-01

    Pretreatment computerized tomography (CT) films of the chest was studied to clarify the influence of interstitial shadow on developing interstitial lung disease (ILD). Eligible patients were those lung cancer patients who started to receive first-line chemotherapy between October 2001 and March 2004. Patients who received thoracic radiotherapy to the primary lesion, mediastinum, spinal or rib metastases were excluded. We reviewed pretreatment conventional CT and plain X-ray films of the chest. Ground-glass opacity, consolidation or reticular shadow without segmental distribution was defined as interstitial shadow, with this event being graded as mild, moderate or severe. If interstitial shadow was detected on CT films of the chest, but not via plain chest X-ray, it was graded as mild. Patients developing ILD were identified from medial records. A total of 502 patients were eligible. Mild, moderate and severe interstitial shadow was identified in 7, 8 and 5% of patients, respectively. A total of 188 patients (37%) received tyrosine kinase inhibitor (TKI) treatment, namely gefitinib or erlotinib. Twenty-six patients (5.2%) developed ILD either during or after chemotherapy. Multivariate analyses revealed that interstitial shadow on CT films of the chest and treatment history with TKI were associated with the onset of ILD. It is recommended that patients with interstitial shadow on chest CT are excluded from future clinical trials until this issue is further clarified, as it is anticipated that use of chemotherapeutic agents frequently mediate onset of ILD in this context. (author)

  16. Microbial contamination of cosmetics and personal care items in Egypt--eye shadows, mascaras and face creams.

    Science.gov (United States)

    Abdelaziz, A A; Ashour, M S; Hefni, H; el-Tayeb, O M

    1989-02-01

    We examined a total of 150 samples, including 27 eye shadows, 27 mascaras and 96 face creams, for their microbial contents. Mascaras were generally more contaminated than eye shadows. More than 75% of the examined eye shadows contained fewer than 100 c.f.u./g aerobic bacterial count compared to 63% of the mascaras examined. Viable bacteria were not recovered from 61% and 48% of the eye shadows and mascaras respectively. While 4% of the eye shadows were heavily contaminated (contained more than 10(4) c.f.u./g), 15% of the mascaras were as heavily contaminated (with more than 10(4) c.f.u./ml of bacteria). Face creams were generally more heavily contaminated than eye shadows and mascaras. More than 70% of the examined creams contained more than 100 c.f.u./g of bacteria compared to 23% and 37% of eye shadows and mascaras respectively. Only 5% of the face creams were heavily contaminated. However, 27% of the creams were contaminated with more than 10(3)-10(4) c.f.u./g of bacteria compared to none in this range for both eye shadows and mascaras. Qualitative tests for detection of hazardous bacteria showed that none of the eye shadows were contaminated with any of those micro-organisms. Out of nine items of a specific brand of mascara, three isolates of Pseudomonas aeruginosa, one isolate of Citrobacter freundii and one isolate of Klebsiella pneumonia were detected. Among the creams, two brands showed the highest contamination levels with more than 85% of the tested samples containing more than 10(3) c.f.u./g fungi and at least 10(4) c.f.u./g bacteria.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Wave Generation Theory

    DEFF Research Database (Denmark)

    Frigaard, Peter; Høgedal, Michael; Christensen, Morten

    The intention of this manual is to provide some formulas and techniques which can be used for generating waves in hydraulic laboratories. Both long crested waves (2-D waves) and short crested waves (3-D waves) are considered.......The intention of this manual is to provide some formulas and techniques which can be used for generating waves in hydraulic laboratories. Both long crested waves (2-D waves) and short crested waves (3-D waves) are considered....

  18. Numerical prediction of wave impact loads on multiple rectangular beams

    DEFF Research Database (Denmark)

    Mayer, Stefan; Nielsen, Kristian Bendix; Hansen, E.A.

    2005-01-01

    corresponding to a wave impact scenario in the experimental database of Sterndorff [2002]. For the case of wave impact on a single structural element the numerical results show good agreement with measured force time histories. In the computations featuring two beams, the prediction of the shadowing effect......Wave impact on one and two structural beams with rectangular cross section is simulated with a two-dimensional finite volume method, solving the unsteady Euler equations and employing a VOF-type method for the description of the free surface. Four different test series are carried out, each...... of the first beam on the second is in reasonable agreement with the experimental data. However, the force peak on the second beam is somewhat over-predicted. The calculations successfully predict a second peak in the force time series of the second beam, which is caused by airborne water shipped over the first...

  19. Morphodynamics of Disequilibrium Wave Ripples

    Science.gov (United States)

    Huppert, K. L.; Koss, A.; Perron, T.; Myrow, P. M.; Southard, J. B.; Wickert, A. D.

    2011-12-01

    Sand ripples, one of the most commonly observed patterns in sedimentary environments, record the complex interplay between fluid flow and sediment transport in aeolian and hydrodynamic systems. Because of a well-known relationship between the wavelength of orbital ripples and the amplitude of wave-generated oscillatory flow, wave ripple patterns preserved in sedimentary rock are important paleoenvironmental indicators used to infer ancient wave conditions. Many previous studies have focused on the development of equilibrium ripple fields, in which the ripples have adjusted to a steady-state wavelength under the imposed flow conditions. However, natural ripple fields are often in disequilibrium because ripples typically evolve over time scales of minutes to hours, and wave conditions rarely remain constant over longer intervals. A complete theory of wave ripple morphodynamics therefore requires an understanding of transient dynamics, but the mechanisms by which two-dimensional ripple fields adjust to changed flow conditions are poorly understood. We performed a series of experiments in a field-scale laboratory wave tank to study the disequilibrium dynamics of orbital ripples. In each experiment, we subjected a level sand bed with small perturbations to constant wave forcing to establish an initial ripple field, and then imposed an abrupt change in wave conditions that would produce a different final ripple wavelength. To control for the influence of boundary shear stress on ripple adjustment rates or mechanisms, the final wave conditions were the same in all experiments. A variety of ripple defects emerged in our experiments during both the formation of an initial ripple field and its adjustment to changed wave conditions, though defects were generally more abundant during the adjustment stage. Different types of defects accommodated lengthening and shortening of the ripple wavelength. When the amplitude of the oscillatory flow was lengthened, cup-like depressions

  20. Finite Amplitude Ocean Waves

    Indian Academy of Sciences (India)

    IAS Admin

    plitude waves and finite amplitude waves. This article provides a brief introduction to finite amplitude wave theories. Some of the general characteristics of waves as well as the importance of finite amplitude wave theories are touched upon. 2. Small Amplitude Waves. The topmost and the lowest levels of the waves are re-.

  1. Observation of the Moon shadow using a new reconstruction technique in the CLUE experiment

    International Nuclear Information System (INIS)

    Dokoutchaeva, V.; Kartashov, D.; Malakhov, N.; Menzione, A.; Smogailov, E.; Marsella, G.; Bartoli, B.; Bastieri, D.; Cresti, M.; Sartori, G.; Sbarra, C.; Saggion, A.; Mariotti, M.; Biral, R.; Pegna, R.; Rosso, F.; Ciocci, M. A.; Scribano, A.; Paoletti, R.; Turini, N.; Stammerra, A.; Liello, F.

    2001-01-01

    The CLUE experiment, located in La Palma island at 2200 m a.s.l., is an array of 3 x 3 telescope, detecting the UV (190-230 nm) Cerenkov light produced by atmospheric showers. Due to the higher atmospheric absorption in the UV range than in the visible one, CLUE cannot apply existing algorithms normally used in IACT experiments to determine primary cosmic ray direction. In this paper it is presented a new method developed by CLUE. The algorithm performances were evaluated using simulated showers. CLUE experiment collected data in the last two years pointing to AGN sources and to Moon. The preliminary results obtained using the new technique on Crab Nebula and on Markarian 421 were presented in a previous paper. Here, it is presented the preliminary observation of Moon Shadow employing the new method. As described in the paper, it is expected in a near future improvements on AGN sources and on Moon Shadow measurement

  2. Observation of the Moon shadow using a new reconstruction technique in the CLUE experiment

    Energy Technology Data Exchange (ETDEWEB)

    Dokoutchaeva, V.; Kartashov, D.; Malakhov, N.; Menzione, A.; Smogailov, E. [Istituto Nazionale di Fisica Nucleare, Pisa (Italy); Marsella, G. [Lecce Univ., Lecce (Italy). Dipt. di Fisica; Istituto Nazionale di Fisica Nucleare, Lecce (Italy); Bartoli, B. [Naples Univ., Naples (Italy). Dipt. di Fisica; Istituto Nazionale di Fisica Nucleare, Naples (Italy); Bastieri, D.; Cresti, M.; Sartori, G.; Sbarra, C.; Saggion, A.; Mariotti, M. [Padua Univ., Padua (Italy). Dipt. di Fisica; Istituto Nazionale di Fisica Nucleare, Padua (Italy); Biral, R.; Pegna, R.; Rosso, F. [Pisa Univ., Pisa (Italy). Dipt. di Fisica; Istituto Nazionale di Fisica Nucleare, Pisa (Italy); Ciocci, M. A.; Scribano, A.; Paoletti, R.; Turini, N. [Siena Univ., Siena (Italy). Dipt. di Fisica; Istituto Nazionale di Fisica Nucleare, Siena (Italy); Stammerra, A. [Turin Univ., Turin (Italy). Dipt. di Fisica; Istituto Nazionale di Fisica Nucleare, Turin (Italy); Liello, F. [Trieste Univ., Trieste (Italy). Dipt. di Fisica; Istituto Nazionale di Fisica Nucleare, Trieste (Italy)

    2001-10-01

    The CLUE experiment, located in La Palma island at 2200 m a.s.l., is an array of 3 x 3 telescope, detecting the UV (190-230 nm) Cerenkov light produced by atmospheric showers. Due to the higher atmospheric absorption in the UV range than in the visible one, CLUE cannot apply existing algorithms normally used in IACT experiments to determine primary cosmic ray direction. In this paper it is presented a new method developed by CLUE. The algorithm performances were evaluated using simulated showers. CLUE experiment collected data in the last two years pointing to AGN sources and to Moon. The preliminary results obtained using the new technique on Crab Nebula and on Markarian 421 were presented in a previous paper. Here, it is presented the preliminary observation of Moon Shadow employing the new method. As described in the paper, it is expected in a near future improvements on AGN sources and on Moon Shadow measurement.

  3. Hybridity in Willa Cather's Death Comes for the Archbishop and Shadows on the Rock

    Directory of Open Access Journals (Sweden)

    Maryam Heydari Fard

    2015-02-01

    Full Text Available Willa Cather wrote Death Comes for the Archbishop and Shadows on the Rock based on the missionary life of Europeans in Quebec and New Mexico. In both novels she depicts a different type of colonizer-colonized relationship. The colonizers arrive with their stereotypical views about the natives to purportedly civilize them. But later, through their interaction with the natives, their superior, patronizing attitude gradually changes, so that, the boundary between the colonizer and the colonized becomes blurred. Contrary to their presuppositions about natives and also the long-established colonial attitude, the missionaries in these two novels treat the natives sympathetically and in some cases equally. Using Homi Bhabha's theory of hybridity, this essay attempts to analyze these two novels in terms of the depiction of cultural relation/interaction. Keywords: Willa Cather, Death Comes for the Archbishop, Shadows on the Rock, Colonialism, Cultural Hybridity

  4. THE SHADOW BANKING SYSTEM AND ITS ROLE IN TRIGGERING THE GLOBAL CRISIS

    Directory of Open Access Journals (Sweden)

    Carmen BOGHEAN

    2015-04-01

    Full Text Available Financial innovation, the deficiencies of corporate governance, moral hazard, easy money policies, government inefficiency, and mainly the activity of the shadow banking system have all played a critical role in setting off the global financial crisis. Due to the imbalances it has triggered, the shadow banking system has been at the core of the most widespread and profound world crisis of all time, as the attempt to use financial capital as efficiently as possible by resorting to “innovative” products has significantly contributed to the advent of the financial crisis. The present crisis has already proved that the banking and financial activity can have a deeply disturbing impact on our economy, but the flexibility of lending mechanisms and the various reactions of the players on the market that are otherwise inherent in a dynamic economic system, cannot exist in the absence of banking mechanisms.

  5. An improved fuzzy c-means clustering algorithm based on shadowed sets and PSO.

    Science.gov (United States)

    Zhang, Jian; Shen, Ling

    2014-01-01

    To organize the wide variety of data sets automatically and acquire accurate classification, this paper presents a modified fuzzy c-means algorithm (SP-FCM) based on particle swarm optimization (PSO) and shadowed sets to perform feature clustering. SP-FCM introduces the global search property of PSO to deal with the problem of premature convergence of conventional fuzzy clustering, utilizes vagueness balance property of shadowed sets to handle overlapping among clusters, and models uncertainty in class boundaries. This new method uses Xie-Beni index as cluster validity and automatically finds the optimal cluster number within a specific range with cluster partitions that provide compact and well-separated clusters. Experiments show that the proposed approach significantly improves the clustering effect.

  6. Chile shadow report to the United Nations sheds light on women's rights.

    Science.gov (United States)

    Farmer, A

    1999-07-01

    Three Chilean women's rights organizations and CRLP presented a Shadow Report to the UN Committee on the Elimination of All Forms of Discrimination Against Women (CEDAW). The 25-page Shadow Report indicates in summary the disappointment of the Chilean women in their government. Although Chile has emerged from its history of military dictatorship and is taking its first steps toward returning to a democratic-style of government, the military and the Catholic Church still exert a very strong influence, especially when it comes to policy making. Chilean people especially women, continue to be tyrannized by repressive attitudes, laws, and policies. This tyrannization is exemplified by the rampant discrimination against women in the prisons and the punishment of those undergoing illegal abortions. In short, women have no rights in Chile, and the government has not done enough to eliminate discrimination against them.

  7. THE OBJECTIFICATION OF DEFINITION OF THE PURCHASING POWER OF CONSUMERS IN SHADOW ECONOMY

    Directory of Open Access Journals (Sweden)

    N. Tyukhtenko

    2016-04-01

    Full Text Available The paper analyzed the level of truthfulness of information as to actual volume revenues of workers of the shadow economy. Revealed results of actual solvency of the local population by goods production, work execution, services rendering. Discovered action of currency fluctuation. Analyzed sales of new cars in Ukraine for 2010-2014. Proposed the method of calculating the correction coefficient with a view to determining the level of objectification purchasing power of consumers in a shadow economy and the potential capacity of the sale market of new cars. Defined the optimal selling price of new vehicles in Kherson. Calculated potential market volume of new vehicles and optimal logistic route of their realization in the Kherson region.

  8. Dose rate laser simulation tests adequacy: Shadowing and high intensity effects analysis

    International Nuclear Information System (INIS)

    Nikiforov, A.Y.; Skorobogatov, P.K.

    1996-01-01

    The adequacy of laser based simulation of the flash X-ray effects in microcircuits may be corrupted mainly due to laser radiation shadowing by the metallization and the non-linear absorption in a high intensity range. The numerical joint solution of the optical equations and the fundamental system of equations in a two-dimensional approximation were performed to adjust the application range of laser simulation. As a result the equivalent dose rate to laser intensity correspondence was established taking into account the shadowing as well as the high intensity effects. The simulation adequacy was verified in the range up to 4·10 11 rad(Si)/s with the comparative laser test of a specially designed test structure

  9. Least squares shadowing sensitivity analysis of a modified Kuramoto–Sivashinsky equation

    International Nuclear Information System (INIS)

    Blonigan, Patrick J.; Wang, Qiqi

    2014-01-01

    Highlights: •Modifying the Kuramoto–Sivashinsky equation and changing its boundary conditions make it an ergodic dynamical system. •The modified Kuramoto–Sivashinsky equation exhibits distinct dynamics for three different ranges of system parameters. •Least squares shadowing sensitivity analysis computes accurate gradients for a wide range of system parameters. - Abstract: Computational methods for sensitivity analysis are invaluable tools for scientists and engineers investigating a wide range of physical phenomena. However, many of these methods fail when applied to chaotic systems, such as the Kuramoto–Sivashinsky (K–S) equation, which models a number of different chaotic systems found in nature. The following paper discusses the application of a new sensitivity analysis method developed by the authors to a modified K–S equation. We find that least squares shadowing sensitivity analysis computes accurate gradients for solutions corresponding to a wide range of system parameters

  10. Social learning in the Anthropocene: Novel challenges, shadow networks, and ethical practices.

    Science.gov (United States)

    Schmidt, Jeremy J

    2017-05-15

    The Anthropocene presents novel challenges for environmental management. This paper considers the challenges that the Anthropocene poses for social learning techniques in adaptive management. It situates these challenges with respect to how anthropogenic forcing on the Earth system affects the conditions required for: (1) The cooperative exercises of social learning; (2) The techniques used for assessing the fit of institutions to social-ecological systems; and, (3) The strategies employed for identifying management targets that are transformed by human action. In view of these challenges, the paper then examines how the practices of shadow networks may provide paths for incorporating a broader, more robust suite of social learning practices in the Anthropocene. The paper emphasizes how novel challenges in the Anthropocene demand increased attention to ethical practices, particularly those that establish center-periphery relationships between social learning communities and shadow networks. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. An Improved Fuzzy c-Means Clustering Algorithm Based on Shadowed Sets and PSO

    Directory of Open Access Journals (Sweden)

    Jian Zhang

    2014-01-01

    Full Text Available To organize the wide variety of data sets automatically and acquire accurate classification, this paper presents a modified fuzzy c-means algorithm (SP-FCM based on particle swarm optimization (PSO and shadowed sets to perform feature clustering. SP-FCM introduces the global search property of PSO to deal with the problem of premature convergence of conventional fuzzy clustering, utilizes vagueness balance property of shadowed sets to handle overlapping among clusters, and models uncertainty in class boundaries. This new method uses Xie-Beni index as cluster validity and automatically finds the optimal cluster number within a specific range with cluster partitions that provide compact and well-separated clusters. Experiments show that the proposed approach significantly improves the clustering effect.

  12. Null geodesics and shadow of a rotating black hole in extended Chern-Simons modified gravity

    International Nuclear Information System (INIS)

    Amarilla, Leonardo; Eiroa, Ernesto F.; Giribet, Gaston

    2010-01-01

    The Chern-Simons modification to general relativity in four dimensions consists of adding to the Einstein-Hilbert term a scalar field that couples to the first-class Pontryagin density. In this theory, which has attracted considerable attention recently, the Schwarzschild metric persists as an exact solution, and this is why this model resists several observational constraints. In contrast, the spinning black hole solution of the theory is not given by the Kerr metric but by a modification of it, so far only known for slow rotation and small coupling constant. In the present paper, we show that, in this approximation, the null geodesic equation can be integrated, and this allows us to investigate the shadow cast by a black hole. We discuss how, in addition to the angular momentum of the solution, the coupling to the Chern-Simons term deforms the shape of the shadow.

  13. Coming Out of the Shadows and the Closet: Visibility Schemas Among Undocuqueer Immigrants.

    Science.gov (United States)

    Cisneros, Jesus; Bracho, Christian

    2018-01-16

    Centering the experiences of 31 undocuqueer immigrants, this study seeks to understand the ways that undocuqueer immigrants negotiate the boundaries of social performance by revealing or concealing their gender, sexuality, and immigration status. Findings of this study reveal how, in order to avoid the constant threat of rejection (both legal and social), undocuqueer immigrants engage visibility schemas and make strategic decisions about coming out of the shadows and the closet across different contexts. Undocuqueer immigrants' narratives reveal the ways the closet resembles the shadows in that both provide protection from the outside world, yet neither are considered suitable places for sustaining life. This study raises implications for both research and policy by considering how the intersection of gender, sexuality, and immigration status nullifies neoliberal narratives of coming out as an empowering process and illustrating the uneven landscapes of social acceptance and political control that undocuqueer immigrants must negotiate.

  14. A New SAR Image Segmentation Algorithm for the Detection of Target and Shadow Regions

    Science.gov (United States)

    Huang, Shiqi; Huang, Wenzhun; Zhang, Ting

    2016-01-01

    The most distinctive characteristic of synthetic aperture radar (SAR) is that it can acquire data under all weather conditions and at all times. However, its coherent imaging mechanism introduces a great deal of speckle noise into SAR images, which makes the segmentation of target and shadow regions in SAR images very difficult. This paper proposes a new SAR image segmentation method based on wavelet decomposition and a constant false alarm rate (WD-CFAR). The WD-CFAR algorithm not only is insensitive to the speckle noise in SAR images but also can segment target and shadow regions simultaneously, and it is also able to effectively segment SAR images with a low signal-to-clutter ratio (SCR). Experiments were performed to assess the performance of the new algorithm on various SAR images. The experimental results show that the proposed method is effective and feasible and possesses good characteristics for general application. PMID:27924935

  15. On the performance of transmit antenna selection based on shadowing side information

    KAUST Repository

    Yilmaz, Ahmet Oǧuz

    2013-01-01

    In this paper, a transmit antenna selection scheme, which is based on shadowing side information, is investigated. In this scheme, the selected single transmit antenna provides the highest shadowing coefficient between a transmitter and a receiver. By the proposed technique, the frequency of the usage of the feedback channel from the receiver to the transmitter and channel estimation complexity at the receiver can be reduced. We study the performance of our proposed technique, and in the analysis, we consider an independent but not identically distributed generalized-K composite fading model. More specifically, exact and closed-form expressions for the outage probability, the moment-generating function, the moments of signal-to-noise ratio, and the average symbol error probability (SEP) are derived. In addition, asymptotic outage probability and SP expressions are also presented to investigate the diversity order and the array gain. Finally, our theoretical performance results are validated by Monte Carlo simulations. © 2012 IEEE.

  16. Preliminary results of the Moon shadow using ARGO-YBJ detector

    International Nuclear Information System (INIS)

    Wang Yungang

    2008-01-01

    ARGO-YBJ is a 'full coverage' air shower detector consisting of Resistive Plate Chambers(RPCs) at the Yangbajing High Altitude Cosmic Ray Laboratory (Tibet, China) at 4300 m a.s.l. (lat=30.11 o N, long=90.53 o E). Using the data collected with a carpet of RPCs (1900 m 2 , about 1/3 of the whole ARGO-YBJ detector), the cosmic ray shadowing effect due to the Moon was studied. The 50% angular resolution is found to be ∼1.2 o with the Chess-board method and the Moon shadow with a significance of 4.9 σ is found displaced by 0.7 o westward and 0.5 o northward with respect to the expected position by the equi-zenith angle Method

  17. Acoustic shadows help gleaning bats find prey, but may be defeated by prey acoustic camouflage on rough surfaces.

    Science.gov (United States)

    Clare, Elizabeth L; Holderied, Marc W

    2015-09-01

    Perceptual abilities of animals, like echolocating bats, are difficult to study because they challenge our understanding of non-visual senses. We used novel acoustic tomography to convert echoes into visual representations and compare these cues to traditional echo measurements. We provide a new hypothesis for the echo-acoustic basis of prey detection on surfaces. We propose that bats perceive a change in depth profile and an 'acoustic shadow' cast by prey. The shadow is more salient than prey echoes and particularly strong on smooth surfaces. This may explain why bats look for prey on flat surfaces like leaves using scanning behaviour. We propose that rather than forming search images for prey, whose characteristics are unpredictable, predators may look for disruptions to the resting surface (acoustic shadows). The fact that the acoustic shadow is much fainter on rougher resting surfaces provides the first empirical evidence for 'acoustic camouflage' as an anti-predator defence mechanism.

  18. Rural-to-urban migration and the shadow wage in LDCs.

    Science.gov (United States)

    Renard, R

    1984-04-01

    "This paper discusses the amount of rural-to-urban migration which will be forthcoming when a new urban job is created for which an institutionally fixed wage above the market-clearing level is offered. A simple formula is proposed to estimate migration response. It can be used to calculate the shadow wage in cost-benefit analysis (CBA) in less developed countries (LDCs)." excerpt

  19. Retrieval of Composition and Shadowing Properties of Saturn's Rings from Cassini UVIS Spectra

    Science.gov (United States)

    Bradley, E. T.; Colwell, J. E.; Esposito, L. W.

    2017-12-01

    The rings of Saturn consist of centimeter-to-meter sized particles that are covered by a layer of regolith whose grains consist of water ice and some small amount of contaminant that is delivered to the rings through micrometeorite impacts. The mixing of the water ice and meteoritic material is affected by inter-particle collisions and from the meteoritic impacts. Two types of mixtures considered in this investigation are 1) discrete grains of water ice and contaminant and 2) grains of water ice with inclusions of contaminant embedded within the grain. The rough regolith-covered surfaces may result in shadowing between grains that darkens the observed rings reflectance spectra. We compared reflectance spectra of the rings at far ultraviolet wavelengths taken by the Cassini UVIS to models of the rings that include a shadowing function with both types of mixtures and with different contaminant materials. One contaminant that we used was the dark material of Comet 67P, where we retrieved the single scattering albedo at UVIS wavelengths from reflectance spectra measured by the ALICE spectrograph on the Rosetta spacecraft. We compared the reflectance over a range of phase angles with a Hapke model that included macroscopic roughness in order to account for shadowing in the Comet 67P material. We retrieved the ring particle albedo at discrete radial regions in the rings using reflectance spectra over a wide range of phase angles. We corrected the retrieved ring particle albedo for roughness using the shadowing function and then compared the "smooth" ring particle albedo to compositional models. We found that a two-component discrete grain model consisting of greater than ninety percent water ice and contaminant from either Triton tholin or material spectrally similar to Comet 67P were indistinguishable when compared to the UVIS spectra. This suggests a common darkening material and/or processing between the rings and Comet 67P.

  20. Design of optical decoders using a polarization-encoded optical shadow-casting scheme

    Science.gov (United States)

    Rizvi, Rizwan A.; Zaheer, K.; Zubairy, M. Zuhail

    1988-12-01

    The design of various decoders in the polarization-encoded optical shadow-casting scheme is presented. A general algorithm is used to design these multioutput combinational logic units with separate and simultaneous generation of outputs. In particular, the design of a binary coded decimal (BCD) to an Octal decoder and a BCD to an Excess-3 converter is presented for a fixed source plane as well as a fixed decoding mask. The results have been verified experimentally.

  1. Implementation of trinary logic in a polarization encoded optical shadow-casting scheme.

    Science.gov (United States)

    Rizvi, R A; Zaheer, K; Zubairy, M S

    1991-03-10

    The design of various multioutput trinary combinational logic units by a polarization encoded optical shadow-casting (POSC) technique is presented. The POSC modified algorithm is employed to design and implement these logic elements in a trinary number system with separate and simultaneous generation of outputs. A detailed solution of the POSC logic equations for a fixed source plane and a fixed decoding mask is given to obtain input pixel coding for a trinary half-adder, full adder, and subtractor.

  2. Error analysis of the phase-shifting technique when applied to shadow moire

    International Nuclear Information System (INIS)

    Han, Changwoon; Han Bongtae

    2006-01-01

    An exact solution for the intensity distribution of shadow moire fringes produced by a broad spectrum light is presented. A mathematical study quantifies errors in fractional fringe orders determined by the phase-shifting technique, and its validity is corroborated experimentally. The errors vary cyclically as the distance between the reference grating and the specimen increases. The amplitude of the maximum error is approximately 0.017 fringe, which defines the theoretical limit of resolution enhancement offered by the phase-shifting technique

  3. Reduced atomic shadowing in HiPIMS: Role of the thermalized metal ions

    Science.gov (United States)

    Oliveira, João Carlos; Ferreira, Fábio; Anders, André; Cavaleiro, Albano

    2018-03-01

    In magnetron sputtering, the ability to tailor film properties depends primarily on the control of the flux of particles impinging on the growing film. Among deposition mechanisms, the shadowing effect leads to the formation of a rough surface and a porous, columnar microstructure. Re-sputtered species may be re-deposited in the valleys of the films surface and thereby contribute to a reduction of roughness and to fill the underdense regions. Both effects are non-local and they directly compete to shape the final properties of the deposited films. Additional control of the bombarding flux can be obtained by ionizing the sputtered flux, because ions can be controlled with respect to their energy and impinging direction, such as in High-Power Impulse Magnetron Sputtering (HiPIMS). In this work, the relation between ionization of the sputtered species and thin film properties is investigated in order to identify the mechanisms which effectively influence the shadowing effect in Deep Oscillation Magnetron Sputtering (DOMS), a variant of HiPIMS. The properties of two Cr films deposited using the same averaged target power by d.c. magnetron sputtering and DOMS have been compared. Additionally, the angle distribution of the Cr species impinging on the substrate was simulated using Monte Carlo-based programs while the energy distribution of the energetic particles bombarding the substrate was evaluated by energy-resolved mass analysis. It was found that the acceleration of the thermalized chromium ions at the substrate sheath in DOMS significantly reduces the high angle component of their impinging angle distribution and, thus, efficiently reduces atomic shadowing. Therefore, a high degree of ionization in HiPIMS results in almost shadowing effect-free film deposition and allows us to deposit dense and compact films without the need of high energy particle bombardment during growth.

  4. A New Extended Kalman Filtering for Shadow/Fading Power Estimation in Mobile Communications

    OpenAIRE

    George P. Pappas; Subramaniam Ganesan; Mohamed A. Zohdy

    2014-01-01

    This paper proposes a New Extended Kalman filter (NEKF) approach to improve local mean power estimation. The method is being validated using a GUI system model and then compared to existing methods, Kalman Filter (KF) with Gaussian and Non-Gaussian noise environments. Our analysis is showing that NEKF is a more accurate method in most situations. NEKF can accurately estimate the parameters and predict states in discrete nonlinear state-space for modeling shadow power.

  5. Reduction potential, shadow prices, and pollution costs of agricultural pollutants in China.

    Science.gov (United States)

    Tang, Kai; Gong, Chengzhu; Wang, Dong

    2016-01-15

    This paper analyses the reduction potential, shadow prices, and pollution costs of agricultural pollutants in China based on provincial panel data for 2001-2010. Using a parameterized quadratic form for the directional output distance function, we find that if agricultural sectors in all provinces were to produce on the production frontier, China could potentially reduce agricultural emissions of chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) by 16.0%, 16.2%, and 20.4%, respectively. Additionally, our results show that the shadow price of TN increased rapidly and continuously, while that of COD and TP fluctuated for the whole period. For the whole country, the average shadow price of COD, TN, and TP are 8266 Yuan/tonne, 25,560 Yuan/tonne, and 10,160 Yuan/tonne, respectively. The regional shadow prices of agricultural pollutants are unbalanced. Furthermore, we show that the pollution costs from emissions of COD, TN, and TP are 6.09% of the annual gross output value of the agricultural sector and are highest in the Western and lowest in the Eastern provinces. Our estimates suggest that there is scope for further pollution abatement and simultaneous output expansion for China's agriculture if farmers promote greater efficiency in their production process. Policymakers are required to dynamically adjust the pollution tax rates and ascertain the initial permit price in an emission trading system. Policymakers should also consider the different pollution costs for each province when making the reduction allocations within the agricultural sector. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Methodological issues in the study of the depiction of cast shadows

    OpenAIRE

    Casati, Roberto

    2003-01-01

    The relationships between art and cognition constitute a very wide set of largely unexplored and at times undefined or much too speculative problems. The field is narrowed down by imposing some constraints. It is proposed that the depiction of cast shadows, in its early history, could provide an ideal case study which conforms to the constraints. This paper addresses some methodological problems of the study of this case. A sample of relevant Renaissance images is discussed. A typology of dep...

  7. Shadow Employment in Transition - A Matter of Choice or No Choice?

    OpenAIRE

    Cichocki, Stanislaw; Tyrowicz, Joanna

    2009-01-01

    Shadow employment may follow from two main labour market failures. In the first, official market labour taxation distortions make it ineffective for some agents to engage in registered employment due to a tax wedge, which makes the revenues from unofficial employment higher than the corresponding official ones (tax evasion hypothesis). The alternative explanation draws to labour market tightness - for workers regular employment may be unattainable, which results in seeking earning opportuniti...

  8. Training Classifiers with Shadow Features for Sensor-Based Human Activity Recognition

    Directory of Open Access Journals (Sweden)

    Simon Fong

    2017-02-01

    Full Text Available In this paper, a novel training/testing process for building/using a classification model based on human activity recognition (HAR is proposed. Traditionally, HAR has been accomplished by a classifier that learns the activities of a person by training with skeletal data obtained from a motion sensor, such as Microsoft Kinect. These skeletal data are the spatial coordinates (x, y, z of different parts of the human body. The numeric information forms time series, temporal records of movement sequences that can be used for training a classifier. In addition to the spatial features that describe current positions in the skeletal data, new features called ‘shadow features’ are used to improve the supervised learning efficacy of the classifier. Shadow features are inferred from the dynamics of body movements, and thereby modelling the underlying momentum of the performed activities. They provide extra dimensions of information for characterising activities in the classification process, and thereby significantly improve the classification accuracy. Two cases of HAR are tested using a classification model trained with shadow features: one is by using wearable sensor and the other is by a Kinect-based remote sensor. Our experiments can demonstrate the advantages of the new method, which will have an impact on human activity detection research.

  9. The Academic Success of East Asian American Youth: The Role of Shadow Education

    Science.gov (United States)

    Byun, Soo-yong; Park, Hyunjoon

    2013-01-01

    Using data from the Education Longitudinal Study, this study assessed the relevance of shadow education to the high academic performance of East Asian American students by examining how East Asian American students differed from other racial/ethnic students in the prevalence, purpose, and effects of using the two forms – commercial test preparation service and private one-to-one tutoring – of SAT coaching, defined as the American style of shadow education. East Asian American students were most likely to take a commercial SAT test preparation course for the enrichment purpose, and benefited most from taking this particular form of SAT coaching. However, this was not the case for private SAT one-to-one tutoring. While black students were most likely to utilize private tutoring for the remedial purpose, the impact of private tutoring was trivial for all racial/ethnic groups including East Asian American students. The authors discussed broader implications of the findings on racial/ethnic inequalities in educational achievement beyond the relevance of shadow education for the academic success of East Asian American students. PMID:24163483

  10. Simulation of vegetation and relief induced shadows on rivers with remote sensing data

    Science.gov (United States)

    Karrasch, Pierre; Hunger, Sebastian

    2017-10-01

    Rivers are the lifelines of our environment. For this reason they are always in the focus of environmental studies. For the assessment of the ecological status of rivers the member states of the European Union have developed different monitoring programs and approaches. The shadowing of a river affects the temperature of the water and also the energy balance of the water body. Therefore changes in temperature also influence the biological and chemical status of rivers and lakes. The main objective of this study is the simulation of the shadowing of a section of the river Freiberger Mulde for a full year. This ensures that effects of different sun positions over the year (azimuth, elevation) and also local topography conditions in the close environment of the river section are taken into account. For all analyses a digital surface model and a digital elevation model with a geometric resolution of 2 m is available. The result of this simulation is a raster layer which represents the theoretical annual hours of shadowing of the river section. The results indicate a decrease of illumination of partly more than 80 %. In future this information can be expanded by means of further affecting factors such as the consideration of the phenological status of deciduous trees in the riparian zone.

  11. The Contribution of the Human Body in Young Children's Explanations About Shadow Formation

    Science.gov (United States)

    Herakleioti, Evagelia; Pantidos, Panagiotis

    2016-02-01

    This paper begins with the view that the generation of meaning is a multimodal process. Props, drawings, graphs, gestures, as well as speech and written text are all mediators through which students construct new knowledge. Each semiotic context makes a unique contribution to the conceptualization of scientific entities. The human body, in particular, can function as a factor in both representation and explanation, serving as a link between verbal discourse and setting. Considering this perspective, a body-based activity was designed for kindergarten children, involving the concept of a shadow. The 3-D arrangement of the light from the light source, the human body (the obstacle), and the resulting shadow plays a central role. Using their own bodies as obstacles to the light, the children were able to explore the direction of the light and to change the relative positions of the light source and the obstacle. They formed hypotheses and were able to test them by moving on the stage. This body-centered activity explicitly incorporates the rectilinear movement of light into the process of shadow formation, while also providing learning through direct experience. Positive effects on learning were achieved for the group of children who participated in the activity, while the video analysis showed that many of the children were able to use their bodies to transfer to a different setting the embodied knowledge they acquired. This, according to researchers in the field of science education, is a powerful indication of conceptual change.

  12. Can tongue shadow in panoramic radiographs be avoided by using the tongue repositioning maneuver?

    Science.gov (United States)

    Cordesmeyer, Robert; Engelke, Wilfried; Sömmer, Christian; Kauffmann, Philipp

    2016-06-01

    The purpose of this study was to evaluate the use of the tongue repositioning maneuver (TRM) during panoramic radiography so as to avoid the error of tongue shadow. A total of 300 panoramic radiographs were evaluated. One hundred and fifty orthopantomograms with conventional positioning technique were used as a control group, while other 150 were taken with the patient performing the TRM. The tongue shadow was measured in each radiograph in the first molar regions bilaterally and in the midsagittal plane. Wilcoxon Mann-Whitney U-Test was used to test the significance difference between the groups. The tongue-palate distance in the study group was reduced from a mean value of 6.4 mm to 1 mm in the right first molar, 8.0 mm to 2.2 mm in the midsagittal region, and 6.6 mm to 1.2 mm in the left first molar position. Statistical evaluation exhibited significant differences of tongue shadow at all measuring sites between study and control group (P tongue position error in panoramic radiography. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Clinical study on the observation of unilateral shadows in the maxillary sinus

    Energy Technology Data Exchange (ETDEWEB)

    Hattori, Hirokazu; Sawada, Tatsuya; Hayano, Yoshiaki; Suzuki, Kenji; Yagisawa, Mikio; Nishimura, Tadao [Fujita Health Univ., Nagoya (Japan). Second Affiliated Hospital

    2000-12-01

    In the everyday examination of patients exhibiting a unilateral shadow in the maxillary sinus upon imaging, the differentiation of chronic sinusitis from other diseases, including malignant tumors, is extremely important. A unilateral shadow in the maxillary sinus was detected on scout films and a subsequent CT examination of the sinus was performed in 108 patients who visited our department between January 1994 and December 1998. Bone destruction was suspected after scout films were taken in 2 patients with malignant tumors. These 2 patients account for only a small percentage of the total patient population, but account for as much as 50% of the patients with malignant tumors. In cases of malignant tumors, the CT images suggesting bone destruction agreed with operative findings. CT seems to be a useful tool for evaluating the condition of the bone. When the density of scout films and CT images were compared, no significant difference was detected, suggesting that scout films can be used for the screening of malignant tumors. The density was (+++) in both the scout films and the CT images of the 2 patients with malignant tumors. Finally, we present a flow chart for the diagnosis of unilateral maxillary sinus shadows that has been recently adopted as the basic protocol used in our department. (author)

  14. Extraction of Black Hole Shadows Using Ridge Filtering and the Circle Hough Transform

    Science.gov (United States)

    Hennessey, Ryan; Akiyama, Kazunori; Fish, Vincent

    2018-01-01

    Supermassive black holes are widely considered to reside at the center of most large galaxies. One of the foremost tasks in modern astronomy is to image the centers of local galaxies, such as that of Messier 87 (M87) and Sagittarius A* at the center of our own Milky Way, to gain the first glimpses of black holes and their surrounding structures. Using data obtained from the Event Horizon Telescope (EHT), a global collection of millimeter-wavelength telescopes designed to perform very long baseline interferometry, new imaging techniques will likely be able to yield images of these structures at fine enough resolutions to compare with the predictions of general relativity and give us more insight into the formation of black holes, their surrounding jets and accretion disks, and galaxies themselves. Techniques to extract features from these images are already being developed. In this work, we present a new method for measuring the size of the black hole shadow, a feature that encodes information about the black hole mass and spin, using ridge filtering and the circle Hough transform. Previous methods have succeeded in extracting the black hole shadow with an accuracy of about 10- 20%, but using this new technique we are able to measure the shadow size with even finer accuracy. Our work indicates that the EHT will be able to significantly reduce the uncertainty in the estimate of the mass of the supermassive black hole in M87.

  15. The shadow map: a general contact definition for capturing the dynamics of biomolecular folding and function.

    Science.gov (United States)

    Noel, Jeffrey K; Whitford, Paul C; Onuchic, José N

    2012-07-26

    Structure-based models (SBMs) are simplified models of the biomolecular dynamics that arise from funneled energy landscapes. We recently introduced an all-atom SBM that explicitly represents the atomic geometry of a biomolecule. While this initial study showed the robustness of the all-atom SBM Hamiltonian to changes in many of the energetic parameters, an important aspect, which has not been explored previously, is the definition of native interactions. In this study, we propose a general definition for generating atomically grained contact maps called "Shadow". The Shadow algorithm initially considers all atoms within a cutoff distance and then, controlled by a screening parameter, discards the occluded contacts. We show that this choice of contact map is not only well behaved for protein folding, since it produces consistently cooperative folding behavior in SBMs but also desirable for exploring the dynamics of macromolecular assemblies since, it distributes energy similarly between RNAs and proteins despite their disparate internal packing. All-atom structure-based models employing Shadow contact maps provide a general framework for exploring the geometrical features of biomolecules, especially the connections between folding and function.

  16. K Coverage Probability of 5G Wireless Cognitive Radio Network under Shadow Fading Effects

    Directory of Open Access Journals (Sweden)

    Ankur S. Kang

    2016-09-01

    Full Text Available Land mobile communication is burdened with typical propagation constraints due to the channel characteristics in radio systems.Also,the propagation characteristics vary form place to place and also as the mobile unit moves,from time to time.Hence,the tramsmission path between transmitter and receiver varies from simple direct LOS to the one which is severely obstructed by buildings,foliage and terrain.Multipath propagation and shadow fading effects affect the signal strength of an arbitrary Transmitter-Receiver due to the rapid fluctuations in the phase and amplitude of signal which also determines the average power over an area of tens or hundreds of meters.Shadowing introduces additional fluctuations,so the received local mean power varies around the area –mean.The present section deals with the performance analysis of fifth generation wireless cognitive radio network on the basis of signal and interference level based k coverage probability under the shadow fading effects.

  17. Segmentation of Shadowed Buildings in Dense Urban Areas from Aerial Photographs

    Directory of Open Access Journals (Sweden)

    Junichi Susaki

    2012-03-01

    Full Text Available Segmentation of buildings in urban areas, especially dense urban areas, by using remotely sensed images is highly desirable. However, segmentation results obtained by using existing algorithms are unsatisfactory because of the unclear boundaries between buildings and the shadows cast by neighboring buildings. In this paper, an algorithm is proposed that successfully segments buildings from aerial photographs, including shadowed buildings in dense urban areas. To handle roofs having rough textures, digital numbers (DNs are quantized into several quantum values. Quantization using several interval widths is applied during segmentation, and for each quantization, areas with homogeneous values are labeled in an image. Edges determined from the homogeneous areas obtained at each quantization are then merged, and frequently observed edges are extracted. By using a “rectangular index”, regions whose shapes are close to being rectangular are thus selected as buildings. Experimental results show that the proposed algorithm generates more practical segmentation results than an existing algorithm does. Therefore, the main factors in successful segmentation of shadowed roofs are (1 combination of different quantization results, (2 selection of buildings according to the rectangular index, and (3 edge completion by the inclusion of non-edge pixels that have a high probability of being edges. By utilizing these factors, the proposed algorithm optimizes the spatial filtering scale with respect to the size of building roofs in a locality. The proposed algorithm is considered to be useful for conducting building segmentation for various purposes.

  18. Ionospheric Bow Waves and Perturbations Induced by the 21 August 2017 Solar Eclipse

    Science.gov (United States)

    Zhang, Shun-Rong; Erickson, Philip J.; Goncharenko, Larisa P.; Coster, Anthea J.; Rideout, William; Vierinen, Juha

    2017-12-01

    During solar eclipses, the Moon's shadow causes a large reduction in atmospheric energy input, including not only the stratosphere but also the thermosphere and ionosphere. The eclipse shadow has a supersonic motion which is theoretically expected to generate atmospheric bow waves, similar to a fast-moving river boat, with waves starting in the lower atmosphere and propagating into the ionosphere. However, previous geographically limited observations have had difficulty detecting these weak waves within the natural background atmospheric variability, and the existence of eclipse-induced ionospheric waves and their evolution in a complex coupling system remain controversial. During the 21 August 2017 eclipse, high fidelity and wide coverage ionospheric observations provided for the first time an oversampled set of eclipse data, using a dense network of Global Navigation Satellite System receivers at ˜2,000 sites in North America. We show the first unambiguous evidence of ionospheric bow waves as electron content disturbances over central/eastern United States, with ˜1 h duration, 300-400 km wavelength and 280 m/s phase speed emanating from and tailing the totality region. We also identify large ionospheric perturbations moving at the supersonic speed of the maximum solar obscuration which are too fast to be associated with known gravity wave or large-scale traveling ionospheric disturbance processes. This study reveals complex interconnections between the Sun, Moon, and Earth's neutral atmosphere and ionosphere and demonstrates persistent coupling processes between different components of the Earth's atmosphere, a topic of significant community interest.

  19. Integral transport multiregion geometrical shadowing factor for the approximate collision probability matrix calculation of infinite closely packed lattices

    International Nuclear Information System (INIS)

    Jowzani-Moghaddam, A.

    1981-01-01

    An integral transport method of calculating the geometrical shadowing factor in multiregion annular cells for infinite closely packed lattices in cylindrical geometry is developed. This analytical method has been programmed in the TPGS code. This method is based upon a consideration of the properties of the integral transport method for a nonuniform body, which together with Bonalumi's approximations allows the determination of the approximate multiregion collision probability matrix for infinite closely packed lattices with sufficient accuracy. The multiregion geometrical shadowing factors have been calculated for variations in fuel pin annular segment rings in a geometry of annular cells. These shadowing factors can then be used in the calculation of neutron transport from one annulus to another in an infinite lattice. The result of this new geometrical shadowing and collision probability matrix are compared with the Dancoff-Ginsburg correction and the probability matrix using constant shadowing on Yankee fuel elements in an infinite lattice. In these cases the Dancoff-Ginsburg correction factor and collision probability matrix using constant shadowing are in difference by at most 6.2% and 6%, respectively

  20. The Relationship between Shadow Economy and Unemployment Rate. A Ardl Causality Analysis for the Case Of Romania

    Directory of Open Access Journals (Sweden)

    Adriana AnaMaria DAVIDESCU

    2015-12-01

    Full Text Available The paper aims to investigate the nature of the relationship between the shadow economy (SE and unemployment rates (both registered and ILO for the case of Romania using Pesaran et al.(2001 bounds tests approach for cointegration. The study uses quarterly data covering the period 2000-2010. The size of Romanian shadow economy is estimated using the currency demand approach based on VECM models, stating that its size is decreasing over the analyzed period, from 36.5% at the end of 2000 to about 31.5% of real GDP at the middle of 2010. To investigate the long-run causal linkages and short-run dynamics between shadow economy and unemployment rate, ARDL cointegration approach is applied. Cointegration test results shows that in short-run both ILO and registered unemployment rate has a negative and statistically significant effect on the size of the shadow economy, while in the long-run the unemployment rates have a positive effect on shadow economy. The ARDL causality results revealed the existence of a long-run unidirectional causality that runs from unemployment rates (registered or ILO to shadow economy. In addition, the CUSUM and CUSUMSQ tests confirm the stability of the both causal relationships.

  1. The "shadow sign": a radiographic differentiation of stainless steel versus titanium spinal instrumentation in spine surgery.

    Science.gov (United States)

    Jones-Quaidoo, Sean M; Novicoff, Wendy; Park, Andrew; Arlet, Vincent

    2011-12-01

    Stainless steel spinal instrumentation has been supplanted in recent years by titanium instrumentation. Knowing whether stainless steel or titanium was used in a previous surgery can guide clinical decision making processes, but frequently the clinician has no way to know what type of metal was used. We describe the radiographic "shadow sign," in which superimposed titanium rods and screws remain radiolucent enough that the contour of the underlying components can be seen on a lateral radiograph, whereas superimposed stainless steel rods and screws are completely radiopaque. This technique was evaluated using a retrospective, randomized, and blinded radiographic comparison of titanium and stainless steel spinal instrumentation. The objective was to determine whether the "shadow sign" can reliably differentiate titanium from stainless steel spinal instrumentation. Lateral radiographs from 16 cases of posterior spinal instrumentation (6 titanium, 6 stainless steel, and 2 replicates of each to assess intraobserver reliability) were randomly selected from a database of cases performed for pediatric scoliosis in a university setting from 2005 to 2009. The cases were randomized then shown to 19 orthopaedic surgery residents, 1 spine fellow, and 2 spine attendings. After the "shadow sign" was described, the surgeons were asked to determine what type of metal each implant was made of. The κ value for both stainless steel and titanium versus the gold standard was 0.83 [standard error (SE) = 0.053], indicating excellent agreement. The κ value for agreement between raters was 0.71 (SE = 0.016) and the κ value for agreement within raters was 0.70 (SE = 0.016), both of which indicated substantial agreement. The "shadow sign" can help a clinician differentiate titanium from stainless steel spinal instrumentation based on radiographic appearance alone. Furthermore, our study reveals that the level of experience in diagnosing spinal lateral radiographs also enhances the use of

  2. Impact of Wave Dragon on Wave Climate

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Tedd, James; Kramer, Morten

    This report is an advisory paper for use in determining the wave dragon effects on hydrography, by considering the effect on the wave climate in the region of a wave dragon. This is to be used in the impact assessment for the Wave Dragon pre-commercial demonstrator.......This report is an advisory paper for use in determining the wave dragon effects on hydrography, by considering the effect on the wave climate in the region of a wave dragon. This is to be used in the impact assessment for the Wave Dragon pre-commercial demonstrator....

  3. Gravitational waves

    CERN Document Server

    Ciufolini, I; Moschella, U; Fre, P

    2001-01-01

    Gravitational waves (GWs) are a hot topic and promise to play a central role in astrophysics, cosmology, and theoretical physics. Technological developments have led us to the brink of their direct observation, which could become a reality in the coming years. The direct observation of GWs will open an entirely new field: GW astronomy. This is expected to bring a revolution in our knowledge of the universe by allowing the observation of previously unseen phenomena, such as the coalescence of compact objects (neutron stars and black holes), the fall of stars into supermassive black holes, stellar core collapses, big-bang relics, and the new and unexpected.With a wide range of contributions by leading scientists in the field, Gravitational Waves covers topics such as the basics of GWs, various advanced topics, GW detectors, astrophysics of GW sources, numerical applications, and several recent theoretical developments. The material is written at a level suitable for postgraduate students entering the field.

  4. Wave Star

    DEFF Research Database (Denmark)

    Kramer, Morten; Frigaard, Peter; Brorsen, Michael

    Nærværende rapport beskriver foreløbige hovedkonklusioner på modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star i perioden 13/9 2004 til 12/11 2004.......Nærværende rapport beskriver foreløbige hovedkonklusioner på modelforsøg udført på Aalborg Universitet, Institut for Vand, Jord og Miljøteknik med bølgeenergianlægget Wave Star i perioden 13/9 2004 til 12/11 2004....

  5. Shadow corrosion phenomenon. An out-of-pile study on electrochemical effects

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Nadine

    2017-04-28

    The focus of the present thesis was the study of the enhanced corrosion phenomenon named ''Shadow Corrosion''. Within the context of researching based on the corrosion mechanism as well as the influencing parameters and driving forces, which cause or even intensify the corrosion, a variety of electrochemical characterization and surface analysis techniques were used. The first part of this thesis gives a short introduction with the definition of the term Shadow Corrosion and of the specific type called ''Enhanced Spacer Shadow Corrosion'' (ESSC). This is followed by a description of the involved materials being Zircaloy and Inconel 718. Chapter 2 introduces the background knowledge including fundamentals about environ-mental conditions under which Shadow Corrosion occurs as well as the oxidation behavior of Zircaloy and Inconel 718. Furthermore, the state of the art about the Shadow Corrosion mechanism is presented and a description of the influencing effects on the enhanced corrosion phenomenon, like galvanic corrosion, water radiolysis, and photo-effect, is given. Further information and parameters on the part of AREVA GmbH concerning water impurities and a used coating layer on Inconel 718 are listed, which are of interest for the issue concerning the phenomenon Shadow Corrosion. The last part of this chapter contains the experimental conditions and parameters for the laboratory experiments with focus on water chemistry, specimen geometry, and UV-light exposure for photoexcitation and water radiolysis. Three different working hypotheses of this thesis are described in chapter 3. One hypothesis regarding the Shadow Corrosion Phenomenon is based on a galvanic corrosion mechanism between Zircaloy and Inconel 718. In addition, it is supposed that the galvanic corrosion could be influenced by the deposition of silver on Zircaloy and Inconel 718 in the form of an increased galvanic current. A further assumption is that the

  6. Shock Waves

    CERN Document Server

    Jiang, Z

    2005-01-01

    The International Symposium on Shock Waves (ISSW) is a well established series of conferences held every two years in a different location. A unique feature of the ISSW is the emphasis on bridging the gap between physicists and engineers working in fields as different as gas dynamics, fluid mechanics and materials sciences. The main results presented at these meetings constitute valuable proceedings that offer anyone working in this field an authoritative and comprehensive source of reference.

  7. Wave Propagation

    CERN Document Server

    Ferrarese, Giorgio

    2011-01-01

    Lectures: A. Jeffrey: Lectures on nonlinear wave propagation.- Y. Choquet-Bruhat: Ondes asymptotiques.- G. Boillat: Urti.- Seminars: D. Graffi: Sulla teoria dell'ottica non-lineare.- G. Grioli: Sulla propagazione del calore nei mezzi continui.- T. Manacorda: Onde nei solidi con vincoli interni.- T. Ruggeri: "Entropy principle" and main field for a non linear covariant system.- B. Straughan: Singular surfaces in dipolar materials and possible consequences for continuum mechanics

  8. Market Pressure on Currencies in Crises. Shadow Exchange Rate Experience of Argentina and Switzerland 2011-2015

    Directory of Open Access Journals (Sweden)

    Marcin Gruszczyński

    2017-10-01

    Full Text Available Aim/purpose - The aim of this article is to present two cases of exchange rate controls in Switzerland and Argentina. The paper also examines the problem of presence and evaluation of shadow exchange rate in both countries. Design/methodology/approach - The shadow exchange rates are estimated using speculative pressure index concept that emphasizes the importance of not only exchange rate movements but also changes in foreign exchange reserves as well as interest rate differentials. The research sample covers Switzerland 2001-2016 and Argentina 2006-2016 (for shadow exchange rate simulation: 2011-2014 and 2011-2015, respectively. Findings - The conclusions drawn from international experience and conducted empirical analysis are positive. In both cases, shadow exchange rates were close to market rates after the removal of controls. During the restrictions periods shadow rates followed the intuition given by speculative pressure index concept (and by monetary approach, simultaneously. Research implications/limitations - The research suggests that market forces in both countries were still able to restore exchange rates to market values after the period of control. However, it is obvious that it is very difficult to prove that shadow rates were always determined by economical forces and close to their long-term equilibrium values. Originality/value/contribution - The original approach combines two important economic concepts - the idea of shadow exchange rate and the methodology of index of speculative pressure. Combined together they can help to analyze two interesting and relatively new cases of foreign exchange controls in Switzerland and Argentina. The results can be valuable for economists, researchers and politicians who support or reject the idea of controlling macroeconomic parameters in modern, open economy.

  9. Making Waves: Seismic Waves Activities and Demonstrations

    Science.gov (United States)

    Braile, S. J.; Braile, L. W.

    2011-12-01

    The nature and propagation of seismic waves are fundamental concepts necessary for understanding the exploration of Earth's interior structure and properties, plate tectonics, earthquakes, and seismic hazards. Investigating seismic waves is also an engaging approach to learning basic principles of the physics of waves and wave propagation. Several effective educational activities and demonstrations are available for teaching about seismic waves, including the stretching of a spring to demonstrate elasticity; slinky wave propagation activities for compressional, shear, Rayleigh and Love waves; the human wave activity to demonstrate P- and S- waves in solids and liquids; waves in water in a simple wave tank; seismic wave computer animations; simple shake table demonstrations of model building responses to seismic waves to illustrate earthquake damage to structures; processing and analysis of seismograms using free and easy to use software; and seismic wave simulation software for viewing wave propagation in a spherical Earth. The use of multiple methods for teaching about seismic waves is useful because it provides reinforcement of the fundamental concepts, is adaptable to variable classroom situations and diverse learning styles, and allows one or more methods to be used for authentic assessment. The methods described here have been used effectively with a broad range of audiences, including K-12 students and teachers, undergraduate students in introductory geosciences courses, and geosciences majors.

  10. Evaluation of different shadow detection and restoration methods and their impact on vegetation indices using UAV high-resolution imageries over vineyards

    Science.gov (United States)

    Aboutalebi, M.; Torres-Rua, A. F.; McKee, M.; Kustas, W. P.; Nieto, H.

    2017-12-01

    Shadows are an unavoidable component of high-resolution imagery. Although shadows can be a useful source of information about terrestrial features, they are a hindrance for image processing and lead to misclassification errors and increased uncertainty in defining surface reflectance properties. In precision agriculture activities, shadows may affect the performance of vegetation indices at pixel and plant scales. Thus, it becomes necessary to evaluate existing shadow detection and restoration methods, especially for applications that makes direct use of pixel information to estimate vegetation biomass, leaf area index (LAI), plant water use and stress, chlorophyll content, just to name a few. In this study, four high-resolution imageries captured by the Utah State University - AggieAir Unmanned Aerial Vehicle (UAV) system flown in 2014, 2015, and 2016 over a commercial vineyard located in the California for the USDA-Agricultural Research Service Grape Remote sensing Atmospheric Profile and Evapotranspiration Experiment (GRAPEX) Program are used for shadow detection and restoration. Four different methods for shadow detection are compared: (1) unsupervised classification, (2) supervised classification, (3) index-based method, and (4) physically-based method. Also, two different shadow restoration methods are evaluated: (1) linear correlation correction, and (2) gamma correction. The models' performance is evaluated over two vegetation indices: normalized difference vegetation index (NDVI) and LAI for both sunlit and shadowed pixels. Histogram and analysis of variance (ANOVA) are used as performance indicators. Results indicated that the performance of the supervised classification and the index-based method are better than other methods. In addition, there is a statistical difference between the average of NDVI and LAI on the sunlit and shadowed pixels. Among the shadow restoration methods, gamma correction visually works better than the linear correlation

  11. Acoustic Gravity Waves in the Ionosphere and Thermosphere During the 2017 Solar Eclipse

    Science.gov (United States)

    Lin, C. Y. T.; Deng, Y.

    2017-12-01

    During the 2017 solar eclipse, as the sudden cavity of solar radiation created by the lunar shadow moves across the United States on August 21, 2017, decreases in local IT temperature and density are expected. The average velocity of the total solar eclipse across the United States is 700 m/s. The forefront and wake of the lunar shadow are expected to induce acoustic gravity waves according to previous studies of atmosphere waves induced by traveling wave packets moving at different velocities. Meanwhile, moving toward the cross-track direction of the obscuration footprint, weaker transitions will likely create mesoscale to large-scale traveling disturbances. We will use the Global Ionosphere Thermosphere Model, a global circulation model solving for non-hydrostatic equations, with high-resolution settings to investigate the IT responses related to the acoustic-gravity wave perturbations during the 2017 solar eclipse. The simulation will be performed with a sub-degree resolution in longitude and latitude for 3 hours when the atmosphere of the North America sector is mostly obscured. The observable differences between the eclipsed and non-eclipsed scenarios will be examined in detail and be interpreted as consequences from the solar eclipse. We will investigate the evolution of waves during the event and establish a theoretical baseline for further comparisons with observations.

  12. Scattering of radio frequency waves by turbulence in fusion plasmas

    Science.gov (United States)

    Ram, Abhay K.

    2016-10-01

    In tokamak fusion plasmas, coherent fluctuations in the form of blobs or filaments and incoherent fluctuations due to turbulence are routinely observed in the scrape-off layer. Radio frequency (RF) electromagnetic waves, excited by antenna structures placed near the wall of a tokamak, have to propagate through the scrape-off layer before reaching the core of the plasma. While the effect of fluctuations on RF waves has not been quantified experimentally, there are telltale signs, arising from differences between results from simulations and from experiments, that fluctuations can modify the spectrum of RF waves. Any effect on RF waves in the scrape-off layer can have important experimental consequences. For example, electron cyclotron waves are expected to stabilize the deleterious neoclassical tearing mode (NTM) in ITER. Spectral and polarization changes due to scattering will modify the spatial location and profile of the current driven by the RF waves, thereby affecting the control of NTMs. Pioneering theoretical studies and complementary computer simulations have been pursued to elucidate the impact of fluctuations on RF waves. From the full complement of Maxwell's equations for cold, magnetized plasmas, it is shown that the Poynting flux in the wake of filaments develops spatial structure due to diffraction and shadowing. The uniformity of power flow into the plasma is affected by side-scattering, modifications to the wave spectrum, and coupling to plasma waves other than the incident RF wave. The Snell's law and the Fresnel equations have been reformulated within the context of magnetized plasmas. They are distinctly different from their counterparts in scalar dielectric media, and reveal new and important physical insight into the scattering of RF waves. The Snell's law and Fresnel equations are the basis for the Kirchhoff approximation necessary to determine properties of the scattered waves. Furthermore, this theory is also relevant for studying back

  13. Short linear shadows connecting pulmonary segmental arteries to oblique fissures in volumetric thin-section CT images: comparing CT, micro-CT and histopathology

    International Nuclear Information System (INIS)

    Guan, Chun-Shuang; Ma, Da-Qing; Chen, Jiang-Hong; Chen, Bu-Dong; Cui, Dun; Zhang, Yan-Song; Liu, Wei-Hua

    2016-01-01

    To retrospectively evaluate short linear shadows connecting pulmonary segmental arteries to oblique fissures in thin-section CT images and determine their anatomical basis. CT scanning was performed on 108 patients and 11 lung specimens with no lung diseases around the oblique fissures or hilar. Two radiologists evaluated the imaging. The parameters included length, thickness of short linear shadows, pulmonary segmental artery variations, and traction interlobar fissures, etc. The short linear shadows were not related to sex, age, or smoking history. The lengths of the short linear shadows were generally within 10 mm. The thicknesses of the short linear shadows ranged from 1 to 2 mm. Of the patients, 26.9 % showed pulmonary segmental artery variations; 66.7 % of short linear shadows pulled oblique fissures. In three-dimensional images, the short linear shadows appeared as arc planes, with one side edge connected to the oblique fissure, one side edge connected to a pulmonary segmental artery. On the tissue slices, the short linear shadow exhibited a band structure composed of connective tissues, small blood vessels, and small lymphatic vessels. Short linear shadows are a type of normal intrapulmonary membranes and can maintain the integrity of the oblique fissures and hilar structure. (orig.)

  14. Usability of multiangular imaging spectroscopy data for analysis of vegetation canopy shadow fraction in boreal forest

    Science.gov (United States)

    Markiet, Vincent; Perheentupa, Viljami; Mõttus, Matti; Hernández-Clemente, Rocío

    2016-04-01

    Imaging spectroscopy is a remote sensing technology which records continuous spectral data at a very high (better than 10 nm) resolution. Such spectral images can be used to monitor, for example, the photosynthetic activity of vegetation. Photosynthetic activity is dependent on varying light conditions and varies within the canopy. To measure this variation we need very high spatial resolution data with resolution better than the dominating canopy element size (e.g., tree crown in a forest canopy). This is useful, e.g., for detecting photosynthetic downregulation and thus plant stress. Canopy illumination conditions are often quantified using the shadow fraction: the fraction of visible foliage which is not sunlit. Shadow fraction is known to depend on view angle (e.g., hot spot images have very low shadow fraction). Hence, multiple observation angles potentially increase the range of shadow fraction in the imagery in high spatial resolution imaging spectroscopy data. To investigate the potential of multi-angle imaging spectroscopy in investigating canopy processes which vary with shadow fraction, we obtained a unique multiangular airborne imaging spectroscopy data for the Hyytiälä forest research station located in Finland (61° 50'N, 24° 17'E) in July 2015. The main tree species are Norway spruce (Picea abies L. karst), Scots pine (Pinus sylvestris L.) and birch (Betula pubescens Ehrh., Betula pendula Roth). We used an airborne hyperspectral sensor AISA Eagle II (Specim - Spectral Imaging Ltd., Finland) mounted on a tilting platform. The tilting platform allowed us to measure at nadir and approximately 35 degrees off-nadir. The hyperspectral sensor has a 37.5 degrees field of view (FOV), 0.6m pixel size, 128 spectral bands with an average spectral bandwidth of 4.6nm and is sensitive in the 400-1000 nm spectral region. The airborne data was radiometrically, atmospherically and geometrically processed using the Parge and Atcor software (Re Se applications Schl

  15. Multi-objective shadow prices point at principles of metabolic regulation.

    Science.gov (United States)

    Sajitz-Hermstein, Max; Nikoloski, Zoran

    2016-08-01

    Perturbations in environmental and intracellular conditions often lead to changes across all cellular layers, from transcription to metabolism. Regulatory mechanisms are key to mediating these changes to maintain homeostasis and to ensure viability. Since changes in metabolic reaction rates are partly due to perturbations in metabolite concentrations, it is expected that metabolites with large effect on those reaction rates which govern metabolic functionality are tightly regulated. The extent of metabolic regulation has been quantified by the sensitivity of an individual metabolic function to changes in metabolite concentrations, in particular by shadow prices in the constraint-based modeling framework. However, the system-wide characterization of the extent to which metabolite concentrations are regulated in the more realistic scenario of multiple contending tasks remains elusive. Here we examine multi-objective shadow prices for the central carbon metabolism of Escherichia coli whose reaction rates are shaped by several contending metabolic functions. We determine shadow prices for sampled solutions of the Pareto front, which characterizes the space of multi-objective optima, for three contending metabolic functions that provide the best agreement with (13)C-labeling experiments. By analyzing the parts of the Pareto front closest to the experimentally determined flux phenotypes, we show that E. coli operates in the vicinity of an area of the Pareto front which facilitates robust and efficient regulation. In addition, we find significant associations between features of the transcriptional regulatory network and the sensitivity of E. coli's metabolic functionality to changes in metabolite concentrations. We demonstrate that the structural constraints of the metabolic network together with data on condition-specific flux phenotypes can be effectively used to dissect metabolic regulation on a system-wide level. Copyright © 2016 The Author(s). Published by Elsevier

  16. Biological data analysis as an information theory problem: multivariable dependence measures and the shadows algorithm.

    Science.gov (United States)

    Sakhanenko, Nikita A; Galas, David J

    2015-11-01

    Information theory is valuable in multiple-variable analysis for being model-free and nonparametric, and for the modest sensitivity to undersampling. We previously introduced a general approach to finding multiple dependencies that provides accurate measures of levels of dependency for subsets of variables in a data set, which is significantly nonzero only if the subset of variables is collectively dependent. This is useful, however, only if we can avoid a combinatorial explosion of calculations for increasing numbers of variables.  The proposed dependence measure for a subset of variables, τ, differential interaction information, Δ(τ), has the property that for subsets of τ some of the factors of Δ(τ) are significantly nonzero, when the full dependence includes more variables. We use this property to suppress the combinatorial explosion by following the "shadows" of multivariable dependency on smaller subsets. Rather than calculating the marginal entropies of all subsets at each degree level, we need to consider only calculations for subsets of variables with appropriate "shadows." The number of calculations for n variables at a degree level of d grows therefore, at a much smaller rate than the binomial coefficient (n, d), but depends on the parameters of the "shadows" calculation. This approach, avoiding a combinatorial explosion, enables the use of our multivariable measures on very large data sets. We demonstrate this method on simulated data sets, and characterize the effects of noise and sample numbers. In addition, we analyze a data set of a few thousand mutant yeast strains interacting with a few thousand chemical compounds.

  17. Performance characteristics of a perforated shadow band under clear sky conditions

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, Michael J. [School of Mechanical Engineering, University of KwaZulu-Natal, Durban (South Africa)

    2010-12-15

    A perforated, non-rotating shadow band is described for separating global solar irradiance into its diffuse and direct normal components using a single pyranometer. Whereas shadow bands are normally solid so as to occult the sensor of a pyranometer throughout the day, the proposed band has apertures cut from its circumference to intermittently expose the instrument sensor at preset intervals. Under clear sky conditions the device produces a saw tooth waveform of irradiance data from which it is possible to reconstruct separate global and diffuse curves. The direct normal irradiance may then be calculated giving a complete breakdown of the irradiance curves without need of a second instrument or rotating shadow band. This paper describes the principle of operation of the band and gives a mathematical model of its shading mask based on the results of an optical ray tracing study. An algorithm for processing the data from the perforated band system is described and evaluated. In an extended trial conducted at NREL's Solar Radiation Research Laboratory, the band coupled with a thermally corrected Eppley PSP produced independent curves for diffuse, global and direct normal irradiance with low mean bias errors of 5.6 W/m{sup 2}, 0.3 W/m{sup 2} and -2.6 W/m{sup 2} respectively, relative to collocated reference instruments. Random uncertainties were 9.7 W/m{sup 2} (diffuse), 17.3 W/m{sup 2} (global) and 19.0 W/m{sup 2} (direct). When the data processing algorithm was modified to include the ray trace model of sensor exposure, uncertainties increased only marginally, confirming the effectiveness of the model. Deployment of the perforated band system can potentially increase the accuracy of data from ground stations in predominantly sunny areas where instrumentation is limited to a single pyranometer. (author)

  18. Validation of large-angle scattering data via shadow-bar experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, S., E-mail: ohnishi@nmri.go.jp [National Maritime Research Institute, 6-38-1, Shinkawa, Mitaka, Tokyo 181-0004 (Japan); Tamaki, S.; Murata, I. [Osaka University, 1-14-16-1, Yamadaoka, Suita-si, Osaka 565-0871 (Japan)

    2016-11-15

    Highlights: • An experiment to validate large-angle scattering cross section is conducted. • Pieces of Nb foil are set behind a shadow bar to obtain the {sup 92m}Nb production rates. • The results calculated using ENDF/B-VI library data exhibit a 57% overestimation. • The adjustment of cross section in large-angle region makes the C/E close to 1. - Abstract: An experiment emphasizing the influence of large-angle scattering on nuclear data was conducted, in which a Fe shadow bar and a Fe slab target were placed before a deuterium–tritium fusion (DT) neutron source. Two Nb foils were set on both sides of the shadow bar in order to monitor the neutron source intensity and to measure the neutrons scattered from the slab target. The {sup 93}Nb(n,2n){sup 92m}Nb reaction rate of the foil was measured following the DT neutron irradiation and calculated using the MCNP5 Monte Carlo radiation transportation code. The {sup 92m}Nb production rates calculated using data from the JEFF-3.1 and JENDL-4.0 libraries agreed with that measured in the experiment, while the result calculated using data from the ENDF/B-VI library exhibited a 57% overestimation. Because the sensitivity of the {sup 92m}Nb production rate to the scattering angular distribution was large in the angular region between scattering direction cosines of −0.9 and −0.4, the scattering angular distribution was adjusted in that region. This adjustment resulted in a calculation-to-experiment ratio close to 1, but had little influence on the existing integral benchmark experiment.

  19. Impact of lamp shadowing and reflection on the fluence rate distribution in a multiple low-pressure UV lamp array.

    Science.gov (United States)

    Jin, Shanshan; Linden, Karl G; Ducoste, Joel; Liu, Dong

    2005-07-01

    Use of mathematical modeling for determination of ultraviolet (UV) fluence in disinfection reactors requires accurate knowledge of the fluence rate distribution in a multiple lamp array. A method for measuring the fluence rate among a multiple lamp array was demonstrated using spherical actinometry. A matrix of four low-pressure UV lamps in air were investigated to evaluate the potential for shadowing and reflection to impact the fluence rate within and surrounding the lamp array. Two fluence rate distribution models were tested to determine the ability to predict the fluence rate distribution measured by the actinometers. Shadowing proved to attenuate UV light. Reflection from the lamp surface added 3-9% to the fluence rate, depending upon position in the reactor. These effects, as well as the fluence rate at various points in the lamp matrix were effectively modeled using RAD-LSI and UVCalc3D fluence rate distribution models. At fluence rates above 8mWcm(-2), the actinometry measured fluence rate was lower than the modeled rate, presumably from saturation of the actinometer solution at high fluence rates (close to the lamp). With multiple lamp reactors, the impact of shadowing can significantly affect fluence rate distribution and thus the level of microbial inactivation. If shadowing is not included in fluence rate distribution models, the fluence rate will be over predicted in the shadow zone of a neighboring lamp, falsely skewing model inactivation predictions.

  20. The shadow, the tyrant and the insane: the east and west dualism in the visual journalism

    Directory of Open Access Journals (Sweden)

    Alberto Klein

    2014-07-01

    Full Text Available This paper explores the East and West dualism considering three images: the shadow, the tyrant and the insane, respectively linked to Osama Bin Laden, Saddam Hussein and Mahmoud Ahmadinejad. These representations, given their occurrence in the media, appear as stereotypes in the visual journalism, being in total opposition to western values, such as illuminism, democracy and reason. From the perspective of the concept of Orientalism, the text also analyzes semiotic procedures which constitute the process of demonization, according to the contribuitions of Ivan Bystrina, Gilbert Durand and Stuart Clark.

  1. Shared Representation of SAR Target and Shadow Based on Multilayer Auto-encoder

    Directory of Open Access Journals (Sweden)

    Sun Zhi-jun

    2013-06-01

    Full Text Available Automatic Target Recognition (ATR of Synthetic Aperture Radar (SAR image is investigated. A SAR feature extraction algorithm based on multilayer auto-encoder is proposed. The method makes use of a probabilistic neural network, Restricted Boltzmann Machine (RBM modeling probability distribution of environment. Through the formation of more expressive multilayer neural network, the deep learning model learns shared representation of the target and its shadow outline reflecting the target shape characteristics. Targets are classified automatically through two recognition models. The experiment results based on the MSTAR verify the effectiveness of proposed algorithm.

  2. Shadow management applied in the first AP1000 project under the islands contract condition

    International Nuclear Information System (INIS)

    Liu Xiao

    2010-01-01

    As the global first AP1000 nuclear project, Sanmen phase I nuclear project itself has many challenges from design, procurement to construction managements for non practical nuclear project and experience can be referenced. Islands contract pattern was adopted by this project and this contract pattern has its own strength and weakness. Considering the negative influence result from the first unit, this project has the great postpone risk. Shadow management here tries to reduce these risks and enhance the project surveillance and control by the owner to promote the final goal of this project. (authors)

  3. Measurement-based Evaluation of the Impact of Large Vehicle Shadowing on V2X Communications

    DEFF Research Database (Denmark)

    Rodriguez, Ignacio; Portela Lopes de Almeida, Erika; Lauridsen, Mads

    2016-01-01

    Upcoming applications, such as autonomous vehicles, will pose strict requirements on the vehicular networks. In order to provide these new services reliably, an accurate understanding of propagation in the vehicular scenarios is needed. In this context, this paper presents a measurement......-based evaluation of large vehicle shadowing at 5.8 GHz in V2X scenarios. The receiver antenna height is fixed to average vehicular height (1.5 m), while the transmitter antennas are located at different heights (1.5, 5, and 7 m) in order to investigate both V2V and V2I scenarios. A truck was used to obstruct...

  4. Cracking ShadowCrypt: Exploring the Limitations of Secure I/O Systems in Internet Browsers

    OpenAIRE

    Freyberger Michael; He Warren; Akhawe Devdatta; Mazurek Michelle L.; Mittal Prateek

    2018-01-01

    An important line of privacy research is investigating the design of systems for secure input and output (I/O) within Internet browsers. These systems would allow for users’ information to be encrypted and decrypted by the browser, and the specific web applications will only have access to the users’ information in encrypted form. The state-of-the-art approach for a secure I/O system within Internet browsers is a system called ShadowCrypt created by UC Berkeley researchers [23]. This paper wi...

  5. A simple approach to atom probe sample preparation by using shadow masks.

    Science.gov (United States)

    Felfer, Peter; McCarroll, Ingrid; Macauley, Chandra; Cairney, Julie M

    2016-01-01

    Here, we present a new method that utilises shadow masks in a broad ion beam system to prepare atom probe samples. It is particularly suited to non-conductors and materials with surface layers such as surface oxides, implanted layers or thin films. This new approach bypasses the focused ion beam (FIB) lift-out step, increasing the sample throughput, dramatically reducing the required FIB beam time and decreasing the complexity of sample preparation. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. The inclusion of shadowing effect in the reaction-rates calculation

    International Nuclear Information System (INIS)

    Monteiro, M.A.M.

    1990-03-01

    A method for the Resonance Integral calculation in the fuel and moderator regions is presented including the Shadowing effect. This effect appears due to the presence of several fuel rods in a infinite moderator region. The method is based on the approximations to the J (ζ, β) function and theirs partial derivatives in relation to β. The dependence of the Resonance Integral in the J (ζ, β) comes from the rational approximation to the neutron escape probability. The final results are obtained in a very simple and fast way, and show the good accuracy of the method. (author)

  7. Hard probes in heavy ion collisions at the LHC: PDFs, shadowing and $pA$ collisions

    CERN Document Server

    Accardi, Alberto; Botje, M.; Brodsky, S.J.; Cole, B.; Eskola, K.J.; Fai, George I.; Frankfurt, L.; Fries, R.J.; Geist, Walter M.; Guzey, V.; Honkanen, H.; Kolhinen, V.J.; Kovchegov, Yu.V.; McDermott, M.; Morsch, A.; Qiu, Jian-wei; Salgado, C.A.; Strikman, M.; Takai, H.; Tapprogge, S.; Vogt, R.; Zhang, X.f.

    2003-01-01

    This manuscript is the outcome of the subgroup ``PDFs, shadowing and $pA$ collisions'' from the CERN workshop ``Hard Probes in Heavy Ion Collisions at the LHC''. In addition to the experimental parameters for $pA$ collisions at the LHC, the issues discussed are factorization in nuclear collisions, nuclear parton distributions (nPDFs), hard probes as the benchmark tests of factorization in $pA$ collisions at the LHC, and semi-hard probes as observables with potentially large nuclear effects. Also, novel QCD phenomena in $pA$ collisions at the LHC are considered. The importance of the $pA$ program at the LHC is emphasized.

  8. From the Islamic “shadow plays” to puppets, passing through “altarpieces of wonders”

    Directory of Open Access Journals (Sweden)

    Federico Corriente

    2014-06-01

    Full Text Available The very etyma of the Castilian words títere ‘puppet-show’ and titiritero ‘puppet-man’, together with that of Catalán babastell ‘stick used to handle the puppets’, controversial items for which we now suggest Arabic origines, again pose thequestion of the relative importance of the Islamic tradition of the “shadow plays” in the development of Western and most particularly Hispanic varieties of puppet theater. Some passages of Don Quixote would support this hypothesis and subsequently receive a new interpretation.

  9. Geomechanical effects of stress shadow created by large-scale destress blasting

    Directory of Open Access Journals (Sweden)

    Isaac Vennes

    2017-12-01

    Full Text Available This study aims to determine if large-scale choked panel destress blasting can provide sufficient beneficial stress reduction in highly-stressed remnant ore pillar that is planned for production. The orebody is divided into 20 stopes over 2 levels, and 2 panels are choke-blasted in the hanging wall to shield the ore pillar by creating a stress shadow around it. A linear-elastic model of the mining system is constructed with finite difference code FLAC3D. The effect of destress blasting in the panels is simulated by applying a fragmentation factor (α to the rock mass stiffness and a stress reduction factor (β to the current state of stress in the region occupied by the destress panels. As an extreme case, the destress panel is also modeled as a void to obtain the maximum possible beneficial effects of destressing and stress shadow. Four stopes are mined in the stress shadow of the panels in 6 lifts and then backfilled. The effect of destress blasting on the remnant ore pillar is quantified based on stress change and brittle shear ratio (BSR in the stress shadow zone compared to the base case without destress blasting. To establish realistic rock fragmentation and stress reduction factors, model results are compared to measured stress changes reported for case studies at Fraser and Brunswick mines. A 1.5 MPa immediate stress decrease was observed 20 m away from the panel at Fraser Mine, and a 4 MPa immediate stress decrease was observed 25 m away at Brunswick Mine. Comparable results are obtained from the current model with a rock fragmentation factor α of 0.2 and a stress reduction factor β of 0.8. It is shown that a destress blasting with these parameters reduces the major principal stress in the nearest stopes by 10–25 MPa. This yields an immediate reduction of BSR, which is deemed sufficient to reduce volume of ore at risk in the pillar.

  10. Van Allen Probes, THEMIS, GOES, and Cluster observations of EMIC waves, ULF pulsations, and an electron flux dropout

    Czech Academy of Sciences Publication Activity Database

    Sigsbee, K.; Kletzing, C. A.; Smith, C. W.; MacDowall, R.; Spence, H.; Reeves, G.; Blake, J. B.; Baker, D. N.; Green, J. C.; Singer, H. J.; Carr, C.; Santolík, Ondřej

    2016-01-01

    Roč. 121, č. 3 (2016), s. 1990-2008 ISSN 2169-9380 Grant - others:AV ČR(CZ) AP1401 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378289 Keywords : EMIC waves * ULF pulsations * electron flux dropouts * Dst effect * magnetopause shadowing * Van Allen Probes Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.733, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/2014JA020877/full

  11. SHADOW GLOBALIZATION

    OpenAIRE

    Larissa Mihaylovna Kapitsa

    2014-01-01

    The article reviews some development trends brought about by globalization, particularly, a growing tax evasion and tax avoidance, an expansion of illicit financial flows and the proliferation of a global criminal network. The author draws attention to some new phenomena, particularly, cosmopolitanization of some parts of national elites and a deepening divide between national interests and the private interests of elites as a consequence of financial globalization. Modern mass media, both Ru...

  12. Shadow Play.

    Science.gov (United States)

    Dugan, Michael; And Others

    This document presents a series of essays on the relations between Australia and its neighboring Asian countries. Several of the essays focus on the history of particular groups of Asians who have lived or still live in Australia. Reasons for, and effects of, migration to Australia are analyzed. Five essays are included: (1) "Australia and…

  13. Thorvaldsen's Shadow

    DEFF Research Database (Denmark)

    Dam Christensen, Hans

    2010-01-01

      This article takes its starting point in a silhouette portrait of the sculptor, Bertel Thorvaldsen (1770-1844), by far the most famous artist of the so-called Golden Age in the history of Danish art. The main purpose is to outline the importance of silhouette portraits in the Danish Golden Age...... as well as their importance in a more general history of visual culture. First and foremost, the article points to the fact that silhouettes once were a very popular way of making portraits, which has been neglected by posterity. Next, it discusses silhouette portraits in a wider context that invites...... a consideration of similarities with for example, from a traditional point of view, neo-classical aesthetics and, from a more critical point of view, racism. Further, the article contest a modern "post-photographic" reception, which makes the silhouettes uninteresting or tedious, in order to promote a "pre...

  14. Thorvaldsen's Shadow

    DEFF Research Database (Denmark)

    Dam Christensen, Hans

    2010-01-01

      This article takes its starting point in a silhouette portrait of the sculptor, Bertel Thorvaldsen (1770-1844), by far the most famous artist of the so-called Golden Age in the history of Danish art. The main purpose is to outline the importance of silhouette portraits in the Danish Golden Age...... as well as their importance in a more general history of visual culture. First and foremost, the article points to the fact that silhouettes once were a very popular way of making portraits, which has been neglected by posterity. Next, it discusses silhouette portraits in a wider context that invites......-photographic" reception of silhouette portraits, where the indexical representation (in a Peircean sense) of a beloved, deceased or missed person is stressed; this "pre-photographic" reception is a mode of affective reception which we nowadays seem to overlook. In other words, the article argues that silhouette portraits...

  15. Moravian Shadows

    Directory of Open Access Journals (Sweden)

    Gavin Keeney

    2003-10-01

    Full Text Available For the rapture of the Dionysian state with its annihilation of the ordinary bounds and limits of existence contains, while it lasts, a lethargic element in which all personal experiences of the past become immersed. This chasm of oblivion separates the worlds of everyday reality and of Dionysian reality. But as soon as this everyday reality re-enters consciousness, it is experienced as such, with nausea: an ascetic, will-negating mood is the fruit of these states (Nietzsche, 1967, pp 59-60. [E]very theory is a working hypothesis fostered by our interest in the facts themselves: theory is essential for sorting out the pertinent facts and ordering them in a system – it is for that and no more. The very need for some particular set of facts, the very prerequisite of having some particular conceptual sign - these are conditions dictated by contemporary life with its specific problems. History is, in effect, a science of complex analogies, a science of double vision: the facts of the past have meanings for us that differentiate them and place them, invariably and inevitably, in a system under the sign of contemporary problems. Thus one set of problems supplants another. History in this sense is a special method of studying the present with the aid of the facts of the past (Ejxenbaum, in Matejka and Pomorska, 2002, p 56.

  16. The effect of LH wave on the peripheral plasma of TM-1-MH tokamak

    International Nuclear Information System (INIS)

    Badalec, J.; Datlov, J.; Jakubka, K.; Kopecky, V.; Koerbel, S.; Kryska, L.; Magula, P.; Stoeckel, J.; Zacek, F.; Nanobashvili, S.

    1983-01-01

    The effect of lower hybrid waves on the parameters of peripheral plasma in the TM-1-MH tokamak is investigated in close connection with a previous study of lower hybrid heating of the plasma core. Radial profiles of the saturated ion current are reconstructed from measurements using a movable Langmuir probe. The enhancement of the saturated ion current observed in a limiter shadow is interpreted as the heating of peripheral ions due to absorption of decay waves generated in this region as a result of the nonlinear wave-plasma interaction. Langmuir probe measurements found no increase in electron temperature or electron density due to direct local absorption of the pump wave. (J.U.)

  17. Finite Amplitude Ocean Waves

    Indian Academy of Sciences (India)

    IAS Admin

    are known as intermediate or transitional water waves and if the depth of the water column is less than 1/20 of wavelength, they are called shallow water waves. In the case of both these waves, the particle motion is elliptical. Particle motions are shown in Figure 1. The velocity of waves is generally referred to as wave.

  18. Automatic Cloud and Shadow Detection in Optical Satellite Imagery Without Using Thermal Bands—Application to Suomi NPP VIIRS Images over Fennoscandia

    Directory of Open Access Journals (Sweden)

    Eija Parmes

    2017-08-01

    Full Text Available In land monitoring applications, clouds and shadows are considered noise that should be removed as automatically and quickly as possible, before further analysis. This paper presents a method to detect clouds and shadows in Suomi NPP satellite’s VIIRS (Visible Infrared Imaging Radiometer Suite satellite images. The proposed cloud and shadow detection method has two distinct features when compared to many other methods. First, the method does not use the thermal bands and can thus be applied to other sensors which do not contain thermal channels, such as Sentinel-2 data. Secondly, the method uses the ratio between blue and green reflectance to detect shadows. Seven hundred and forty-seven VIIRS images over Fennoscandia from August 2014 to April 2016 were processed to train and develop the method. Twenty four points from every tenth of the images were used in accuracy assessment. These 1752 points were interpreted visually to cloud, cloud shadow and clear classes, then compared to the output of the cloud and shadow detection. The comparison on VIIRS images showed 94.2% correct detection rates and 11.1% false alarms for clouds, and respectively 36.1% and 82.7% for shadows. The results on cloud detection were similar to state-of-the-art methods. Shadows showed correctly on the northern edge of the clouds, but many shadows were wrongly assigned to other classes in some cases (e.g., to water class on lake and forest boundary, or with shadows over cloud. This may be due to the low spatial resolution of VIIRS images, where shadows are only a few pixels wide and contain lots of mixed pixels.

  19. Analysis of the impacts of Wave Energy Converter arrays on the nearshore wave climate in the Pacific Northwest

    Science.gov (United States)

    O'Dea, A.; Haller, M. C.

    2013-12-01

    As concerns over the use of fossil fuels increase, more and more effort is being put into the search for renewable and reliable sources of energy. Developments in ocean technologies have made the extraction of wave energy a promising alternative. Commercial exploitation of wave energy would require the deployment of arrays of Wave Energy Converters (WECs) that include several to hundreds of individual devices. Interactions between WECs and ocean waves result in both near-field and far-field changes in the incident wave field, including a significant decrease in wave height and a redirection of waves in the lee of the array, referred to as the wave shadow. Nearshore wave height and direction are directly related to the wave radiation stresses that drive longshore currents, rip currents and nearshore sediment transport, which suggests that significant far-field changes in the wave field due to WEC arrays could have an impact on littoral processes. The goal of this study is to investigate the changes in nearshore wave conditions and radiation stress forcing as a result of an offshore array of point-absorber type WECs using a nested SWAN model, and to determine how array size, configuration, spacing and distance from shore influence these changes. The two sites of interest are the Northwest National Marine Renewable Energy Center (NNMREC) test sites off the coast of Newport Oregon, the North Energy Test Site (NETS) and the South Energy Test Site (SETS). NETS and SETS are permitted wave energy test sites located approximately 4 km and 10 km offshore, respectively. Twenty array configurations are simulated, including 5, 10, 25, 50 and 100 devices in two and three staggered rows in both closely spaced (three times the WEC diameter) and widely spaced (ten times the WEC diameter) arrays. Daily offshore wave spectra are obtained from a regional WAVEWATCH III hindcast for 2011, which are then propagated across the continental shelf using SWAN. Arrays are represented in SWAN

  20. Study On Budget Revenue Collection, Shadow Economy and Tax Losses Caused By It

    Directory of Open Access Journals (Sweden)

    Radu Claudia Florina

    2017-06-01

    Full Text Available Tax avoidance is a phenomenon faced by all countries, to a lesser or greater extent, and we can say that it has begun to manifest itself since the introduction of taxes. It is known that generally taxes are not pleasing to taxpayers, especially when their level is high. However, it is important for individuals, as a whole, not to evade from their tax obligations. In this context taxes can be regarded as a necessary evil to ensure the resources needed for state functioning. But often some taxpayers are looking for ways to avoid taxes, engaging either in tax evasion to the shelter of the law or in fraudulent evasion. In this paper we present some of the aspects that motivate individuals to pay taxes. Also we analyze the situation of budgetary revenues in Alba County and also the evolution of the main income of consolidated general budget in Romania. In the end of the paper we intend to draw a parallel between shadow economy, tax burden and tax losses due to shadow economy for a sample of 32 countries. In this way we can see where underground economy and tax losses have the highest values and where are required measures to mitigate them.

  1. Aliens and existential elevators: absurdity and its shadows in Douglas Adams’s Hitch hiker series

    Directory of Open Access Journals (Sweden)

    M.A. van der Colff

    2008-07-01

    Full Text Available According to twentieth-century existentialist philosophy, the universe as we know it is steeped in senselessness, and the only possible means of survival is the construction of subjective meaning. Douglas Adams’s fictional universe portrayed in his “Hitch hiker” series reflects the arbitrary nature of existence, and the characters dwelling in this narrative space are faced with two existential choices: the one is defiance in the face of senselessness, the other is bleak despair. This article explores the existential choices made by prominent characters in the “Hitch hiker” series. The article distinguishes between and analyses the Sisyphus characters and their polar opposites (or nihilist shadows in Douglas Adams’s “Hitch hiker” series. Adams’s characters, be they human, alien or sentient machine, all face the same existential choice: actuate individual meaning, or resort to despondency. Characters who choose the first option are regarded as Sisyphus figures, whereas characters who choose the latter are referred to as shadows or nihilist nemeses.

  2. Study of African Dust with Multi-Wavelength Raman Lidar During "Shadow" Campaign in Senegal

    Science.gov (United States)

    Veselovskii, Igor; Goloub, Philippe; Podvin, Thierry; Bovchaliuk, Valentyn; Tanre, Didier; Derimian, Yevgeny; Korenskiy, Mikhail; Dubovik, Oleg

    2016-06-01

    West Africa and the adjacent oceanic regions are very important locations for studying dust properties and their influence on weather and climate. The SHADOW (Study of SaHAran Dust Over West Africa) campaign is performing a multi-scale and multi-laboratory study of aerosol properties and dynamics using a set of in situ and remote sensing instruments at an observation site located at IRD (Institute for Research and Development) Center, Mbour, Senegal (14°N, 17°W). In this paper, we present the results of lidar measurements performed during the first phase of SHADOW which occurred in March-April, 2015. The multiwavelength Mie-Raman lidar acquired 3β+2α+1δ measurements during this period. This set of measurements has permitted particle intensive properties such as extinction and backscattering Ångström exponents (BAE) for 355/532 nm wavelengths corresponding lidar ratios and depolarization ratio at 532 nm to be determined. The backscattering Ångström exponent during the dust episodes decreased to ~-0.7, while the extinction Ångström exponent though being negative, was greater than -0.2. Low values of BAE can likely be explained by an increase in the imaginary part of the dust refractive index at 355 nm compared to 532 nm.

  3. Vehicle detection based on the use of shadow region and edge

    Science.gov (United States)

    Jeong, Sangheon; Kang, Seongkoo; Kim, Joongkyu

    2013-07-01

    Automotive and advanced driver assistance systems have attracted a great deal of attention lately. In these systems, effective and reliable vehicle detection is important because such systems can reduce the number of accidents and save human' lives. This paper describes an approach to detecting a forward vehicle using a camera mounted on the moving vehicle. In this paper, we describe two methods to detect a vehicle on the road. First, by using the vehicle's shadow, we can obtain the general location of the vehicular candidate. Second, we can identify the strong vertical edges at the left and right position of a vehicle. By combining the shadows and the edge, we can detect the vehicle's location. But other regions may also be detected, such as car windows, reflections, and illumination by the sun. In order to remove these other factors, defined as noises, we need to use a filter. After using the filter, we can calculate the exact location of the vehicle. Additionally, by using connected component labeling, we can obtain coordinates and establish the vehicle's location. Connected component labeling find all connected components in an image and assigns a unique label to all points in the same component. These methods are very useful for vehicle detection and the development of the driving assistance systems, and they can protect drivers' safety from having an accident.

  4. Model planetary nebulae: the effect of shadowed filaments on low ionization potential ion radiation

    International Nuclear Information System (INIS)

    Katz, A.

    1977-01-01

    Previous homogeneous model planetary nebulae calculations No. 4 have yielded emission strengths for low ionization potential No. 4 ions which are considerably lower than those observed. Several attempts were to correct this problem by the inclusion of optically thin condensations, the use of energy flux distributions from stellar model calculations instead of blackbody spectrum stars, and the inclusion of dust in the nebulae. The effect that shadowed filaments have on the ionization and thermal structure of model nebulae and the resultant line strengths are considered. These radial filaments are shielded from the direct stellar ionizing radiation by optically thick condensations in the nebula. Theoretical observational evidence exists for the presence of condensations and filaments. Since the only source of ionizing photons in the shadowed filaments is due to diffuse photons produced by recombination, ions of lower ionization potential are expected to exist there in greater numbers than those found in the rest of the nebula. This leads to increased line strengths from these ions and increases their values to match the observational values. It is shown that these line strengths in the filaments increase by over one to two orders of magnitude relative to values found in homogeneous models. This results in an increase of approximately one order of magnitude for these lines when contributions from both components of the nebula are considered. The parameters that determine the exact value of the increase are the radial location of the filaments in the nebula and the fraction of the nebular volume occupied by the filaments

  5. Gnomon shadow lengths recorded in the Zhoubi Suanjing: the earliest meridian observations in China?

    International Nuclear Information System (INIS)

    Li Yong; Sun Xiaochun

    2009-01-01

    The Zhoubi Suanjing, one of the most important ancient Chinese books on mathematical astronomy, was compiled about 100 BC in the Western Han dynasty (BC 206 - AD 23). We study the gnomon shadow lengths for the 24 solar terms as recorded in the book. Special attention is paid to the so-called law of 'cun qian li', which says the shadow length of a gnomon of 8 chi (about 1.96 m) high will increase (or decrease) 1 cun (1/10 chi) for every 1000 li (roughly 400 km) the gnomon moves northward (or southward). From these data, one can derive the time and location of the observations. The results, however, do not fit historical facts. We suggest that compilers of the Zhoubi Suanjing must have modified the original data according to the law of 'cun qian li'. Through reversing the situation, we recovered the original data, our analysis of which reveals the best possible observation time as 564 BC and the location of observation as 35.78 deg. N latitude. We conclude that this must be the earliest records of solar meridian observations in China. In the meantime, we give the errors of solar altitudes for the 24 solar terms. The average deviation is 5.22 deg., and the mean absolute deviation is 5.52 deg., signifying the accuracy of astronomical calculations from that time.

  6. Gnomon shadow lengths recorded in the Zhoubi Suanjing: the earliest meridian observations in China?

    Science.gov (United States)

    Li, Yong; Sun, Xiao-Chun

    2009-12-01

    The Zhoubi Suanjing, one of the most important ancient Chinese books on mathematical astronomy, was compiled about 100 BC in the Western Han dynasty (BC 206 - AD 23). We study the gnomon shadow lengths for the 24 solar terms as recorded in the book. Special attention is paid to the so-called law of 'cun qian li', which says the shadow length of a gnomon of 8 chi (about 1.96 m) high will increase (or decrease) 1 cun (1/10 chi) for every 1000 li (roughly 400 km) the gnomon moves northward (or southward). From these data, one can derive the time and location of the observations. The results, however, do not fit historical facts. We suggest that compilers of the Zhoubi Suanjing must have modified the original data according to the law of 'cun qian li'. Through reversing the situation, we recovered the original data, our analysis of which reveals the best possible observation time as 564 BC and the location of observation as 35.78° N latitude. We conclude that this must be the earliest records of solar meridian observations in China. In the meantime, we give the errors of solar altitudes for the 24 solar terms. The average deviation is 5.22°, and the mean absolute deviation is 5.52°, signifying the accuracy of astronomical calculations from that time.

  7. GRAY CNVUFAC, Black-Body Radiation View Factors with Self-Shadowing

    International Nuclear Information System (INIS)

    Wong, R.L.

    1991-01-01

    Description of program or function: CNVUFAC, the General Dynamics heat-transfer radiation view program, was adapted for use on the LLNL computer system. The input and output were modified, and a node incrementing logic added for compatibility with TRUMP (NESC 771) thermal analyzer and related codes. The program performs the multiple integration necessary to evaluate the geometric black-body radiation node to node view factors. CNVUFAC uses an elemental area summation scheme to evaluate the multiple integrals. The program permits shadowing and self-shadowing. The basic configuration shapes that can be considered are cylinders, cones, spheres, ellipsoids, flat plates, disks, toroids, and polynomials of revolution. Portions of these shapes can also be considered. Card-image output containing node number and view factor information is generated for input to GRAY, a related code. GRAY performs the matrix manipulations necessary to convert black-body radiation heat-transfer view factors to gray-body view factors as required by thermal analyzer codes. The black-body view factors contain only geometric relationships. GRAY allows the effects of multiple gray-body reflections to be included. The resulting effective gray-body view factors can then be used with the corresponding fourth-power temperature differences to obtain the net radiative heat flux. GRAY accepts a matrix input or the card-image output generated by CNVUFAC. The resulting card-image GRAY output is in a form usable by TRUMP

  8. Optical properties of black holes in the presence of a plasma: The shadow

    Science.gov (United States)

    Abdujabbarov, Ahmadjon

    2016-07-01

    We have studied photon motion around axially symmetric rotating Kerr black holes in the presence of a plasma with radial power-law density. It is shown that in the presence of a plasma, the observed shape and size of the shadow changes depending on the (i) plasma parameters, (ii) black hole spin, and (iii) inclination angle between the observer plane and the axis of rotation of the black hole. In order to extract the pure effect of the plasma influence on the black hole image, the particular case of the Schwarzschild black hole has also been investigated and it has been shown that the photon sphere around the spherically symmetric black hole is left unchanged under the plasma influence; however, the Schwarzschild black hole shadow size in the plasma is reduced due to the refraction of the electromagnetic radiation in the plasma environment of the black hole. The study of the energy emission from the black hole in plasma environment shows that in the presence of the plasma the maximal energy emission rate from the black hole decreases.

  9. Perception of object illumination depends on highlights and shadows, not shading.

    Science.gov (United States)

    Pas, Susan F Te; Pont, Sylvia C; Dalmaijer, Edwin S; Hooge, Ignace T C

    2017-07-01

    Human observers are able to successfully infer direction and intensity of light from photographed scenes despite complex interactions between light, shape, and material. We investigate how well they are able to distinguish other low-level aspects of illumination, such as the diffuseness and the number of light sources. We use photographs of a teapot, an orange, and a tennis ball from the ALOI database (Geusebroek, Burghouts, & Smeulders, 2005) to create different illumination conditions, varying either in diffuseness of a single light source or in separation angle between two distinct light sources. Our observers were presented with all three objects; they indicated which object was illuminated differently from the other two. We record discrimination performance, reaction times, and eye fixations. We compare the data to a model that uses differences in image structure in same-object comparisons, and outcomes suggest that participants mostly rely on the information contained in cast shadows and highlights. The pattern of eye fixations confirms this, showing that after the first fixation, observers mostly fixate cast shadow areas. However, information in the highlights is rather salient, so it might be available from first fixation, making separate fixations are unnecessary.

  10. Thinking of the Shadow. Conceptions of Cruelty in the History of Western Thought

    Directory of Open Access Journals (Sweden)

    Giorgio Baruchello

    2018-03-01

    Full Text Available As regards thinking of the shadow, I can contribute to the present discussion qua intellectual historian who, together with the theologian Michael Trice, has reconstructed in recent years the understanding of a particular manifestation of the shadow in the long life of Western philosophy: cruelty. Between 1998, when I started investigating Judith Shklar’s and Richard Rorty’s liberalism of fear, and 2017, when I completed a volume of collected essays of mine to be published by Northwest Passage Books under the title Philosophy of Cruelty, I devoted considerable time and attention to retrieving, mapping and reflecting upon the conceptions of cruelty developed in the history of Western thought. What follows here is a concise overview of the five most common and/or most articulate conceptions that I have identified in the course of my studies, and repeats almost verbatim what I state in the aforementioned collection of essays of mine. Longer and more detailed analyses can be retrieved in my older publications on this subject. Please note also that my research is intentionally limited to explicit uses of the terms “cruelty” and “cruel” in the languages accessible to me. Extending it to cognates such as “violence” or “aggressiveness” would make the project unmanageable.

  11. Making waves in a photoactive polymer film

    Science.gov (United States)

    Gelebart, Anne Helene; Jan Mulder, Dirk; Varga, Michael; Konya, Andrew; Vantomme, Ghislaine; Meijer, E. W.; Selinger, Robin L. B.; Broer, Dirk J.

    2017-06-01

    Oscillating materials that adapt their shapes in response to external stimuli are of interest for emerging applications in medicine and robotics. For example, liquid-crystal networks can be programmed to undergo stimulus-induced deformations in various geometries, including in response to light. Azobenzene molecules are often incorporated into liquid-crystal polymer films to make them photoresponsive; however, in most cases only the bending responses of these films have been studied, and relaxation after photo-isomerization is rather slow. Modifying the core or adding substituents to the azobenzene moiety can lead to marked changes in photophysical and photochemical properties, providing an opportunity to circumvent the use of a complex set-up that involves multiple light sources, lenses or mirrors. Here, by incorporating azobenzene derivatives with fast cis-to-trans thermal relaxation into liquid-crystal networks, we generate photoactive polymer films that exhibit continuous, directional, macroscopic mechanical waves under constant light illumination, with a feedback loop that is driven by self-shadowing. We explain the mechanism of wave generation using a theoretical model and numerical simulations, which show good qualitative agreement with our experiments. We also demonstrate the potential application of our photoactive films in light-driven locomotion and self-cleaning surfaces, and anticipate further applications in fields such as photomechanical energy harvesting and miniaturized transport.

  12. Millimeter waves sensor modeling and simulation

    Science.gov (United States)

    Latger, Jean; Cathala, Thierry

    2015-10-01

    Guidance of weapon systems relies on sensors to analyze targets signature. Defense weapon systems also need to detect then identify threats also using sensors. One important class of sensors are millimeter waves radar systems that are very efficient for seeing through atmosphere and/or foliage for example. This type of high frequency radar can produce high quality images with very tricky features such as dihedral and trihedral bright points, shadows and lay over effect. Besides, image quality is very dependent on the carrier velocity and trajectory. Such sensors systems are so complex that they need simulation to be tested. This paper presents a state of the Art of millimeter waves sensor models. A short presentation of asymptotic methods shows that physical optics support is mandatory to reach realistic results. SE-Workbench-RF tool is presented and typical examples of results are shown both in the frame of Synthetic Aperture Radar sensors and Real Beam Ground Mapping radars. Several technical topics are then discussed, such as the rendering technique (ray tracing vs. rasterization), the implementation (CPU vs. GP GPU) and the tradeoff between physical accuracy and performance of computation. Examples of results using SE-Workbench-RF are showed and commented.

  13. A CFAR algorithm for layover and shadow detection in InSAR images based on kernel density estimation

    Science.gov (United States)

    Qin, Xianxiang; Zhou, Shilin; Zou, Huanxin; Ren, Yun

    2013-07-01

    In this paper, a novel CFAR algorithm for detecting layover and shadow areas in Interferometric synthetic aperture radar (InSAR) images is proposed. Firstly, the probability density function (PDF) of the square root amplitude of InSAR image is estimated by the kernel density estimation. Then, a CFAR algorithm combining with the morphological method for detecting both layover and shadow is presented. Finally, the proposed algorithm is evaluated on a real InSAR image obtained by TerraSAR-X system. The experimental results have validated the effectiveness of the proposed method.

  14. Shadow effects in simulated ultrasound images derived from computed tomography images using a focused beam tracing model

    DEFF Research Database (Denmark)

    Pham, An Hoai; Lundgren, Bo; Stage, Bjarne

    2012-01-01

    Simulation of ultrasound images based on computed tomography (CT) data has previously been performed with different approaches. Shadow effects are normally pronounced in ultrasound images, so they should be included in the simulation. In this study, a method to capture the shadow effects has been......Focus ultrasound scanner (BK Medical, Herlev, Denmark) equipped with a dedicated research interface giving access to beamformed radio frequency data. CT images were obtained with an Aquilion ONE Toshiba CT scanner (Toshiba Medical Systems Corp., Tochigi, Japan). CT data were mapped from Hounsfield units...

  15. Shadowing para Aproximar la Solución de problemas Parabólicos Semilineales para intervalos de Tiempo Grandes.

    OpenAIRE

    Zavaleta Calderón, Ulices; Aragonéz Salazar, Nelson; Rodríguez, Roxana

    2015-01-01

    Se presenta un resultado de shadowing para un problema de evolucion parabolico no autonomo. Utilizando el metodo de Euler hacia atras se demuestra que bajo ciertas hipótesis de regularidad se puede aproximar usando shadowing la solucion de un problema de la forma                               u'(t) = A(t)u(t) + f(t);donde A(t) es el generador de un semigrupo analítico sobre un espacio de Banach.

  16. Gravitational-wave astronomy

    Science.gov (United States)

    Press, W. H.; Thorne, K. S.

    1972-01-01

    The significance of experimental evidence for gravitational waves is considered for astronomy. Properties, generation, and astrophysical sources of the waves are discussed. Gravitational wave receivers and antennas are described. A review of the Weber experiment is presented.

  17. Snakes from the Leeward Group, Venezuela and eastern Colombia

    NARCIS (Netherlands)

    Brongersma, L.D.

    1940-01-01

    Dr. P. Wagenaar Hummelinck entrusted me with the study of the snakes, which he collected during his trips to the islands off the north coast of Venezuela, to the Venezuelan mainland, and to eastern Colombia. In the present paper the species collected by Dr. Hummelinck are listed with data on scale

  18. Atom Wave Interferometers

    National Research Council Canada - National Science Library

    Pritchard, David

    1999-01-01

    Matter wave interferometers, in which de Broglie waves are coherently split and then recombined to produce interference fringes, have opened exciting new possibilities for precision and fundamental...

  19. Using Multiple Methods to teach ASTR 101 students the Path of the Sun and Shadows

    Science.gov (United States)

    D'Cruz, Noella L.

    2015-01-01

    It seems surprising that non-science major introductory astronomy students find the daily path of the Sun and shadows created by the Sun challenging to learn even though both can be easily observed (provided students do not look directly at the Sun). In order for our students to master the relevant concepts, we have usually used lecture, a lecture tutorial (from Prather, et al.) followed by think-pair-share questions, a planetarium presentation and an animation from the Nebraska Astronomy Applet Project to teach these topics. We cover these topics in a lecture-only, one semester introductory astronomy course at Joliet Junior College. Feedback from our Spring 2014 students indicated that the planetarium presentation was the most helpful in learning the path of the Sun while none of the four teaching methods was helpful when learning about shadows cast by the Sun. Our students did not find the lecture tutorial to be much help even though such tutorials have been proven to promote deep conceptual change. In Fall 2014, we continued to use these four methods, but we modified how we teach both topics so our students could gain more from the tutorial. We hoped our modifications would cause students to have a better overall grasp of the concepts. After our regular lecture, we gave a shorter than usual planetarium presentation on the path of the Sun and we asked students to work through a shadow activity from Project Astro materials. Then students completed the lecture tutorial and some think-pair-share questions. After this, we asked students to predict the Sun's path on certain days of the year and we used the planetarium projector to show them how well their predictions matched up. We ended our coverage of these topics by asking students a few more think-pair-share questions. In our poster, we will present our approach to teaching these topics in Fall 2014, how our Fall 2014 students feel about our teaching strategies and how they fared on related test questions.

  20. Modeling the Magnetopause Shadowing Loss during the October 2012 Dropout Event

    Science.gov (United States)

    Tu, Weichao; Cunningham, Gregory

    2017-04-01

    The relativistic electron flux in Earth's outer radiation belt are observed to drop by orders of magnitude on timescales of a few hours, which is called radiation belt dropouts. Where do the electrons go during the dropouts? This is one of the most important outstanding questions in radiation belt studies. Radiation belt electrons can be lost either by precipitation into the atmosphere or by transport across the magnetopause into interplanetary space. The latter mechanism is called magnetopause shadowing, usually combined with outward radial diffusion of electrons due to the sharp radial gradient it creates. In order to quantify the relative contribution of these two mechanisms to radiation belt dropout, we performed an event study on the October 2012 dropout event observed by Van Allen Probes. First, the precipitating MeV electrons observed by multiple NOAA POES satellites at low altitude did not show evidence of enhanced precipitation during the dropout, which suggested that precipitation was not the dominant loss mechanism for the event. Then, in order to simulate the magnetopause shadowing loss and outward radial diffusion during the dropout, we applied a radial diffusion model with electron lifetimes on the order of electron drift periods outside the last closed drift shell. In addition, realistic and event-specific inputs of radial diffusion coefficients (DLL) and last closed drift shell (LCDS) were implemented in the model. Specifically, we used the new DLL developed by Cunningham [JGR 2016] which were estimated in realistic TS04 [Tsyganenko and Sitnov, JGR 2005] storm time magnetic field model and included physical K (2nd adiabatic invariant) or pitch angle dependence. Event-specific LCDS traced in TS04 model with realistic K dependence was also implemented. Our simulation results showed that these event-specific inputs are critical to explain the electron dropout during the event. The new DLL greatly improved the model performance at low L* regions (L*<3

  1. Impact of Wind Shear and Tower Shadow Effects on Power System with Large Scale Wind Power Penetration

    DEFF Research Database (Denmark)

    Hu, Weihao; Su, Chi; Chen, Zhe

    2011-01-01

    presents a simulation model of a variable speed wind farm with permanent magnet synchronous generators (PMSGs) and fullscale back-to-back converters in the simulation tool of DIgSILENT/PowerFactory. In this paper, the impacts of wind shear and tower shadow effects on the small signal stability of power...

  2. Polarization-encoded optical shadow-casting arithmetic-logic-unit design: separate and simultaneous output generation.

    Science.gov (United States)

    Ahmed, J U; Awwal, A A

    1992-09-10

    A memory-efficient dual cell and a multioutput parallel arithmetic logic unit are designed by using a polarization-encoded optical shadow-casting scheme. The design algorithms for identifying the source patterns, input encoding, and output mask are also presented.

  3. Evaluation and comparison of signal to noise ratio according to histogram equalization of heart shadow on chest image

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Won [Dept. of Radiology, Kyung Hee University Hospital at Gang-dong, Seoul (Korea, Republic of); Lee, Eul Kyu [Inje Paik University Hospital at Jeo-dong, Seoul (Korea, Republic of); Jeong, Hoi Woun [The Baekseok Culture University, Cheonan (Korea, Republic of); Kang, Byung Sam; Kim, Hyun Soo; Min, Jung Whan; Son, Jin Hyun [The Shingu University, Seongnam (Korea, Republic of)

    2017-06-15

    The purpose of this study was to measure signal to noise ratio (SNR) according to change of equalization from region of interest (ROI) of heart shadow in chest image. We examined images of chest image of 87 patients in a University-affiliated hospital, Seoul, Korea. Chest images of each patient were calculated by using Image. We have analysis socio-demographical variables, SNR according to images, 95% confidence according to SNR of difference in a mean of SNR. Differences of SNR among change of equalization were tested by SPSS Statistics21 ANOVA test for there was statistical significance 95%(p < 0.05). In SNR results, with the quality of distributions in the order of original chest image, original chest image heart shadow and equalization chest image, equalization chest image heart shadow(p < 0.001). In conclusion, this study would be that quantitative evaluation of heart shadow on chest image can be used as an adjunct to the histogram equalization chest image.

  4. Shadow Analysis Technique for Extraction of Building Height using High Resolution Satellite Single Image and Accuracy Assessment

    Science.gov (United States)

    Raju, P. L. N.; Chaudhary, H.; Jha, A. K.

    2014-11-01

    These High resolution satellite data with metadata information is used to extract the height of the building using shadow. Proposed approach divides into two phases 1) rooftop and shadow extraction and 2) height estimation. Firstly the rooftop and shadow region were extracted by manual/ automatic methods using Example - Based and Rule - Based approaches. After feature extraction next step is estimating height of the building by taking rooftop in association with shadow using Ratio Method and by using the relation between sun-satellite geometry. The performance analysis shows the total mean error of height is 0.67 m from ratio method, 1.51 m from Example - Based Approach and 0.96 m from Rule - Based Approach. Analysis concluded that Ratio Method i.e. manual method is best for height estimation but it is time consuming so the automatic Rule Based approach is best for height estimation in comparison to Example Based Approach because it require more knowledge and selection of more training samples as well as slows the processing rate of the method.

  5. Peer-to-peer shadowing as a technique for the development of nurse middle managers clinical leadership : an explorative study

    NARCIS (Netherlands)

    Pieterbas Lalleman; G.A.C. Smid; J. Rasiah; J. Bouma; M.J. Schuurmans

    2017-01-01

    The purpose of this study was to explore the experiences and impact of peer-to-peer shadowing as a technique to develop nurse middle managers’ clinical leadership practices. A qualitative descriptive study was conducted to gain insight into the experiences of nurse middle managers using

  6. Does body shadow improve the efficacy of virtual reality-based training with BTS NIRVANA?: A pilot study.

    Science.gov (United States)

    Russo, Margherita; De Luca, Rosaria; Naro, Antonino; Sciarrone, Francesca; Aragona, Bianca; Silvestri, Giuseppe; Manuli, Alfredo; Bramanti, Alessia; Casella, Carmela; Bramanti, Placido; Calabrò, Rocco Salvatore

    2017-09-01

    Aim of the present study was to evaluate whether the presence of body shadows during virtual reality (VR) training with BTS NIRVANA (BTs-N) may lead to a better functional recovery. We enrolled 20 poststroke rehabilitation inpatients, who underwent a neurocognitive-rehabilitative training consisting of 24 sessions (3 times a week for 8 weeks) of BTs-N. All the patients were randomized into 2 groups: semi-immersive virtual training with (S-IVTS group) or without (S-IVT group) body shadows. Each participant was evaluated before (T0) and immediately (T1) after the end of the training (Trial Registration Number: NCT03095560). The S-IVTS group showed a greater improvement in visuo-constructive skills and sustained attention, as compared with the S-IVT group. The other measures showed nonsignificant within-group and between-group differences. Our results showed that body shadow may represent a high-priority class of stimuli that act by "pushing" attention toward the body itself. Further studies are needed to clarify the role of body shadow in promoting the internal representation construction and thus self-recognition.

  7. Path Loss, Shadow Fading, and Line-Of-Sight Probability Models for 5G Urban Macro-Cellular Scenarios

    DEFF Research Database (Denmark)

    Sun, Shu; Thomas, Timothy; Rappaport, Theodore S.

    2015-01-01

    This paper presents key parameters including the line-of-sight (LOS) probability, large-scale path loss, and shadow fading models for the design of future fifth generation (5G) wireless communication systems in urban macro-cellular (UMa) scenarios, using the data obtained from propagation...

  8. The Impact of a Computer-Mediated Shadowing Activity on ESL Speaking Skill Development: A Pilot Study

    Science.gov (United States)

    Mishima, Masakazu; Cheng, Lixia

    2017-01-01

    This pilot study explored the instructional value and potential of a computer-mediated shadowing activity for improving English as a Second Language (ESL) learners' speech intelligibility. Prospective International Teaching Assistants (ITAs), who were enrolled in an ESL classroom communication class at a large public university, completed a…

  9. The Shadow of Hate: A History of Intolerance in America. Student Text ("Us and Them") and Teacher's Guide.

    Science.gov (United States)

    Carnes, Jim; Roberson, Houston

    "The Shadow of Hate" resource kit provides a videotape program (40 minutes), 20 copies of a 128-page student text ("Us and Them"), and a 32-page teacher's guide. This document consists of single copies of the two printed components of this kit. The resource traces the history of racial, religious, and social intolerance in the…

  10. Effects of ramp reset pulses on the address discharge in a shadow mask plasma display panel

    International Nuclear Information System (INIS)

    Yang Lanlan; Tu Yan; Zhang Xiong; Jiang Youyan; Zhang Jian; Wang Baoping

    2007-01-01

    A two-dimensional self-consistent numerical simulation model is used to analyse the effects of the ramp reset pulses on the address discharge in a shadow mask plasma display panel (SM-PDP). Some basic parameters such as the slope of the ramp pulse and the terminal voltage of the ramp reset period are varied to investigate their effects. The simulation results illustrate that the wall voltage is mainly decided by the terminal voltage and the firing voltage at the end of the ramp reset period. Moreover, the variation of the ramp slope will also bring a few modifications to the wall voltage. The priming particles in the beginning of the addressing period are related to the slope of the ramping down voltage pulse. The simulation results can help us optimize the driving scheme of the SM-PDP

  11. Ultrasound and Perforated Viscus; Dirty Fluid, Dirty Shadows, and Peritoneal Enhancement

    Directory of Open Access Journals (Sweden)

    Hamid Shokoohi

    2016-04-01

    Full Text Available Early detection of free air in the peritoneal cavity is vital in diagnosis of life-threatening emergencies, and can play a significant role in expediting treatment. We present a series of cases in which bedside ultrasound (US in the emergency department accurately identified evidence of free intra-peritoneal air and echogenic (dirty free fluid consistent with a surgical final diagnosis of a perforated hollow viscus. In all patients with suspected perforated viscus, clinicians were able to accurately identify the signs of pneumoperitoneum including enhanced peritoneal stripe sign (EPSS, peritoneal stripe reverberations, and focal air collections associated with dirty shadowing or distal multiple reflections as ring down artifacts. In all cases, hollow viscus perforation was confirmed surgically. It seems that, performing US in patients with suspected perforated viscus can accurately identify presence of intra-peritoneal echogenic or “dirty” free fluid as well as evidence of free air, and may expedite patient management.

  12. Shadow netWorkspace: An open source intranet for learning communities

    Directory of Open Access Journals (Sweden)

    James M Laffey

    2006-02-01

    Full Text Available Shadow netWorkspace (SNS is a web application system that allows a school or any type of community to establish an intranet with network workspaces for all members and groups. The goal of SNS has been to make it easy for schools and other educational organizations to provide network services in support of implementing a learning community. SNS is open source software using the GNU General Public License (GPL. The software is freely available, and can be downloaded and distributed under the terms of the GPL. SNS is an ongoing project and this instructional development report describes the system, some ways that it is being used, and some key lessons learned from the development and initial deployment of SNS.

  13. Shadow-free multimers as extreme-performance meta-atoms

    Science.gov (United States)

    Safari, M.; Albooyeh, M.; Simovski, C. R.; Tretyakov, S. A.

    2018-02-01

    We generalize the concept of parity-time symmetric structures with the goal to create meta-atoms exhibiting extraordinary abilities to overcome the presumed limitations in the scattering of overall lossless particles, such as nonzero forward scattering and the equality of scattering and extinction powers for all lossless particles. Although the forward scattering amplitude and the extinction cross section of our proposed meta-atoms vanish, they scatter incident energy into other directions, with controllable directionality. These meta-atoms possess extreme electromagnetic properties not achievable for passive scatterers. As an example, we study meta-atoms consisting of two or three small dipole scatterers. We consider possible microwave realizations in the form of short dipole antennas loaded by lumped elements. The proposed meta-atom empowers extraordinary response of a shadow-free scatterer and theoretically enables most unusual material properties when used as a building block of an artificial medium.

  14. Least Squares Shadowing Sensitivity Analysis of Chaotic Flow Around a Two-Dimensional Airfoil

    Science.gov (United States)

    Blonigan, Patrick J.; Wang, Qiqi; Nielsen, Eric J.; Diskin, Boris

    2016-01-01

    Gradient-based sensitivity analysis has proven to be an enabling technology for many applications, including design of aerospace vehicles. However, conventional sensitivity analysis methods break down when applied to long-time averages of chaotic systems. This breakdown is a serious limitation because many aerospace applications involve physical phenomena that exhibit chaotic dynamics, most notably high-resolution large-eddy and direct numerical simulations of turbulent aerodynamic flows. A recently proposed methodology, Least Squares Shadowing (LSS), avoids this breakdown and advances the state of the art in sensitivity analysis for chaotic flows. The first application of LSS to a chaotic flow simulated with a large-scale computational fluid dynamics solver is presented. The LSS sensitivity computed for this chaotic flow is verified and shown to be accurate, but the computational cost of the current LSS implementation is high.

  15. The Performance of Identity in Kamila Shamsie’s Burnt Shadows

    Directory of Open Access Journals (Sweden)

    Daniela Vitolo

    2016-05-01

    Full Text Available The paper discusses the processes of identity construction enacted by the main character in the novel Burnt Shadows by Kamila Shamsie focusing on the performative relationship existing between agency and identity. The aim is to explore the ways in which the author portrays the relationship between relevant political facts and the dynamics of identity formation. Such events can indeed become a driving force to enact a process of identity formation that questions certain social conventions. In the novel historical events become a drive to agency and thus to the performative construction of the self. Such a construction process brings the protagonist of Shamsie’s novel to develop a position highly critical of nationalisms and nationalistic policies and to embrace the idea of possible transnational solidarities.

  16. Bounds on absolutely maximally entangled states from shadow inequalities, and the quantum MacWilliams identity

    Science.gov (United States)

    Huber, Felix; Eltschka, Christopher; Siewert, Jens; Gühne, Otfried

    2018-04-01

    A pure multipartite quantum state is called absolutely maximally entangled (AME), if all reductions obtained by tracing out at least half of its parties are maximally mixed. Maximal entanglement is then present across every bipartition. The existence of such states is in many cases unclear. With the help of the weight enumerator machinery known from quantum error correction and the shadow inequalities, we obtain new bounds on the existence of AME states in dimensions larger than two. To complete the treatment on the weight enumerator machinery, the quantum MacWilliams identity is derived in the Bloch representation. Finally, we consider AME states whose subsystems have different local dimensions, and present an example for a 2×3×3×3 system that shows maximal entanglement across every bipartition.

  17. Thermal Analyses of Apollo Lunar Soils Provide Evidence for Water in Permanently Shadowed Areas

    Science.gov (United States)

    Cooper, Bonnie L.; Smith, M. C.; Gibson, E. K.

    2011-01-01

    Thermally-evolved-gas analyses were performed on the Apollo lunar soils shortly after their return to Earth [1-8]. The analyses revealed the presence of water evolving at temperatures above 200 C. Of particular interest are samples that were collected from permanently-shadowed locations (e.g., under a boulder) with a second sample collected in nearby sunlight, and pairs in which one was taken from the top of a trench, and the second was taken at the base of the trench, where the temperature would have been -10 to -20 C prior to the disturbance [9]. These samples include 63340/63500, 69941/69961, and 76240/76280. At the time that this research was first reported, the idea of hydrated minerals on the lunar surface was somewhat novel. Nevertheless, goethite was observed in lunar breccias from Apollo 14 [10], and it was shown that goethite, hematite and magnetite could originate in an equilibrium assemblage of lunar rocks

  18. ShadowNet: An Active Defense Infrastructure for Insider Cyber Attack Prevention

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xiaohui [ORNL; Beaver, Justin M [ORNL; Treadwell, Jim N [ORNL

    2012-01-01

    The ShadowNet infrastructure for insider cyber attack prevention is comprised of a tiered server system that is able to dynamically redirect dangerous/suspicious network traffic away from production servers that provide web, ftp, database and other vital services to cloned virtual machines in a quarantined environment. This is done transparently from the point of view of both the attacker and normal users. Existing connections, such as SSH sessions, are not interrupted. Any malicious activity performed by the attacker on a quarantined server is not reflected on the production server. The attacker is provided services from the quarantined server, which creates the impression that the attacks performed are successful. The activities of the attacker on the quarantined system are able to be recorded much like a honeypot system for forensic analysis.

  19. Performance Improvement of Partially Shaded Photovoltaic Arrays under Moving Shadow Conditions through Shade Dispersion

    Science.gov (United States)

    Vijayalekshmy, S.; Bindu, G. R.; Rama Iyer, S.

    2016-12-01

    Photovoltaic arrays, which are prone to partial shading (PS) reduce the output power than the real power rating of the array. This paper presents the comparative analyses on the electrical characteristics and power losses of a conventional totally cross tied (TCT) configuration, and rearranged TCT (RTCT) in which the modules are physically rearranged in such a way that there is an improvement of power output of array under moving illumination condition (moving cloud). In RTCT, the physical position of the modules is organized based on the Sudoku puzzle pattern so as to scatter the shading effect over the entire array. The rearrangement of modules is performed without varying the electrical connection of the modules in the array. It is validated that the power generation of array under amoving shadow condition is enhanced and the various PS losses are reduced in rearranged configuration.

  20. Comparison of ultrasound and computer tomography in the diagnosis of pleural shadowing

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, B.; Schmitt, W.G.H.

    1983-05-01

    Sonography was performed in 40 patients with pleural shadowing of uncertain origin in order to complement conventional X-ray examination. Where the findings were not clear-cut, computer tomography was performed subsequently and the diagnosis ascertained by biopsy or operation. Fluid-containing pleural lesions, such as encysted effusions and empyemas, pericardial cysts and one echinococcus cyst were identified by sonography from their appearance and biopsy was performed; computer tomography adds little additional information in these conditions. Solid pleural masses, on the other hand, can be more accurately defined by computer tomography. This shows the entire pleura, including small areas of calcification. Density measurements are able to differentiate various tissues, and particularly fat.